From c9ec675cb00d38adf431cfd55e416a39b05620ba Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Fri, 12 Sep 2025 09:42:27 -0700
Subject: [PATCH 01/17] SGP30 / SGP40 background sampling

Add SGP30 / SGP40 background sampling. Requires frequently 1s polling or returns 0 values.
---
 src/components/i2c/WipperSnapper_I2C.cpp      |  6 ++
 .../i2c/drivers/WipperSnapper_I2C_Driver.h    | 18 +++-
 .../drivers/WipperSnapper_I2C_Driver_SGP30.h  | 69 +++++++++++----
 .../drivers/WipperSnapper_I2C_Driver_SGP40.h  | 84 ++++++++++++++++---
 4 files changed, 148 insertions(+), 29 deletions(-)

diff --git a/src/components/i2c/WipperSnapper_I2C.cpp b/src/components/i2c/WipperSnapper_I2C.cpp
index 7e02c9922..73f6cbf21 100644
--- a/src/components/i2c/WipperSnapper_I2C.cpp
+++ b/src/components/i2c/WipperSnapper_I2C.cpp
@@ -1347,6 +1347,11 @@ void WipperSnapper_Component_I2C::update() {
   msgi2cResponse.which_payload =
       wippersnapper_signal_v1_I2CResponse_resp_i2c_device_event_tag;
 
+  // one fast pass for all drivers every update() call
+  for (auto *drv : drivers) {
+    if (drv) drv->fastTick();
+  }
+
   long curTime;
   bool sensorsReturningFalse = true;
   int retries = 3;
@@ -1354,6 +1359,7 @@ void WipperSnapper_Component_I2C::update() {
   while (sensorsReturningFalse && retries > 0) {
     sensorsReturningFalse = false;
     retries--;
+    curTime = millis();
 
     std::vector<WipperSnapper_I2C_Driver *>::iterator iter, end;
     for (iter = drivers.begin(), end = drivers.end(); iter != end; ++iter) {
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
index e76532719..109dbca5c 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
@@ -34,7 +34,7 @@ class WipperSnapper_I2C_Driver {
 public:
   /*******************************************************************************/
   /*!
-      @brief    Instanciates an I2C sensor.
+      @brief    Instanctiates an I2C sensor.
       @param    i2c
                 The I2C hardware interface, default is Wire.
       @param    sensorAddress
@@ -53,6 +53,20 @@ class WipperSnapper_I2C_Driver {
   /*******************************************************************************/
   virtual ~WipperSnapper_I2C_Driver() {}
 
+  /*******************************************************************************/
+  /*!
+      @brief    Per-update background hook for drivers that need faster internal
+                sampling than the user publish interval.
+                Default is a no-op; override in concrete drivers (e.g., SGP30/40)
+                to maintain required ~1 Hz reads and accumulate/condition
+                values for later publish.
+      @note     Call site: WipperSnapper_Component_I2C::update() will invoke
+                this once per loop for each driver. Implementations must be
+                non-blocking (do not delay); use millis()-based timing.
+  */
+  /*******************************************************************************/
+  virtual void fastTick() {}
+
   /*******************************************************************************/
   /*!
       @brief    Initializes the I2C sensor and begins I2C.
@@ -1312,7 +1326,7 @@ class WipperSnapper_I2C_Driver {
       @brief    Updates the properties of a proximity sensor.
       @param    period
                 The time interval at which to return new data from the
-                proimity sensor.
+                proximity sensor.
   */
   /*******************************************************************************/
   virtual void updateSensorProximity(float period) {
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
index 664695191..2a4d5ff1e 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
@@ -24,6 +24,7 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
       : WipperSnapper_I2C_Driver(i2c, sensorAddress) {
     _i2c = i2c;
     _sensorAddress = sensorAddress;
+    _sgp30 = nullptr;
   }
 
   /*******************************************************************************/
@@ -31,9 +32,12 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
       @brief    Destructor for an SGP30 sensor.
   */
   /*******************************************************************************/
-  ~WipperSnapper_I2C_Driver_SGP30() {
+  ~WipperSnapper_I2C_Driver_SGP30() override {
     // Called when a SGP30 component is deleted.
-    delete _sgp30;
+    if (_sgp30) {
+      delete _sgp30;
+      _sgp30 = nullptr;
+    }
   }
 
   /*******************************************************************************/
@@ -42,29 +46,60 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
       @returns  True if initialized successfully, False otherwise.
   */
   /*******************************************************************************/
-  bool begin() {
+  bool begin() override {
     _sgp30 = new Adafruit_SGP30();
-    return _sgp30->begin(_i2c);
+    if (!_sgp30->begin(_i2c)) {
+      delete _sgp30;          // avoid leak on init failure
+      _sgp30 = nullptr;
+      return false;
+    }
+    _sgp30->IAQinit();           // start IAQ algorithm
+    _lastFastMs = millis();       // reset fast sampler
+    _n = _eco2Sum = _tvocSum = 0; // clear accumulators
+    return true;
   }
 
-  bool getEventECO2(sensors_event_t *senseEvent) {
-    bool result = _sgp30->IAQmeasure();
-    if (result) {
-      senseEvent->eCO2 = _sgp30->eCO2;
-    }
-    return result;
+  bool getEventECO2(sensors_event_t *senseEvent) override {
+    if (!_sgp30) return false;
+    bool ok = _sgp30->IAQmeasure();
+    if (ok) senseEvent->eCO2 = _sgp30->eCO2;
+    return ok;
+  }
+
+  bool getEventTVOC(sensors_event_t *senseEvent) override {
+    if (!_sgp30) return false;
+    bool ok = _sgp30->IAQmeasure();
+    if (ok) senseEvent->tvoc = _sgp30->TVOC;
+    return ok;
   }
 
-  bool getEventTVOC(sensors_event_t *senseEvent) {
-    bool result = _sgp30->IAQmeasure();
-    if (result) {
-      senseEvent->tvoc = _sgp30->TVOC;
+  void fastTick() override {
+    if (!iaqEnabled())
+      return; // nothing enabled, save cycles
+    uint32_t now = millis();
+    if (now - _lastFastMs >= 1000) { // ~1 Hz cadence
+      if (_sgp30 && _sgp30->IAQmeasure()) {
+        _eco2Sum += _sgp30->eCO2;   // uint16_t in library
+        _tvocSum += _sgp30->TVOC;   // uint16_t in library
+        _n++;
+      }
+      _lastFastMs = now;
     }
-    return result;
   }
 
 protected:
-  Adafruit_SGP30 *_sgp30; ///< Pointer to SGP30 temperature sensor object
+  Adafruit_SGP30 *_sgp30; ///< Pointer to SGP30 sensor object
+
+  // Fast sampling state
+  uint32_t _lastFastMs = 0;
+  uint32_t _n = 0;
+  uint32_t _eco2Sum = 0;
+  uint32_t _tvocSum = 0;
+
+  inline bool iaqEnabled() const {
+    // Enable IAQ background reads if either metric is requested
+    return (getSensorECO2Period() > 0) || (getSensorTVOCPeriod() > 0);
+  }
 };
 
-#endif // WipperSnapper_I2C_Driver_SGP30
\ No newline at end of file
+#endif // WipperSnapper_I2C_Driver_SGP30
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
index 3e201b106..b615698bb 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
@@ -40,6 +40,21 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
       : WipperSnapper_I2C_Driver(i2c, sensorAddress) {
     _i2c = i2c;
     _sensorAddress = sensorAddress;
+    _sgp40 = nullptr;
+  }
+
+  /*******************************************************************************/
+  /*!
+      @brief    Destructor for an SGP40 sensor driver.
+                Cleans up and deallocates the underlying Adafruit_SGP40 object
+                when the driver is destroyed.
+  */
+  /*******************************************************************************/
+  ~WipperSnapper_I2C_Driver_SGP40() override {
+    if (_sgp40) {
+      delete _sgp40;
+      _sgp40 = nullptr;
+    }
   }
 
   /*******************************************************************************/
@@ -48,14 +63,17 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
       @returns  True if initialized successfully, False otherwise.
   */
   /*******************************************************************************/
-  bool begin() {
+  bool begin() override {
     _sgp40 = new Adafruit_SGP40();
-    if (!_sgp40->begin(_i2c)) {
+    if (!_sgp40 || !_sgp40->begin(_i2c)) {
+      delete _sgp40;
+      _sgp40 = nullptr;
       return false;
     }
-
-    // TODO: update to use setCalibration() and pass in temp/humidity
-
+    _lastFastMs = millis();
+    _n = 0;
+    _vocSum = 0.0f;
+    _rawSum = 0;
     return true;
   }
 
@@ -64,11 +82,19 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
       @brief    Gets the sensor's current raw unprocessed value.
       @param    rawEvent
                 Pointer to an Adafruit_Sensor event.
-      @returns  True if the temperature was obtained successfully, False
+      @returns  True if the raw value was obtained successfully, False
                 otherwise.
   */
   /*******************************************************************************/
-  bool getEventRaw(sensors_event_t *rawEvent) {
+  bool getEventRaw(sensors_event_t *rawEvent) override {
+    if (!_sgp40) return false;
+    if (_n > 0) {
+      rawEvent->data[0] = (float)_rawSum / (float)_n;
+      _rawSum = 0;
+      _vocSum = 0.0f;
+      _n = 0;
+      return true;
+    }
     rawEvent->data[0] = (float)_sgp40->measureRaw();
     return true;
   }
@@ -82,13 +108,51 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
                 otherwise.
   */
   /*******************************************************************************/
-  bool getEventVOCIndex(sensors_event_t *vocIndexEvent) {
+  bool getEventVOCIndex(sensors_event_t *vocIndexEvent) override {
+    if (!_sgp40) return false;
+    if (_n > 0) {
+      vocIndexEvent->voc_index = _vocSum / (float)_n;
+      _rawSum = 0;
+      _vocSum = 0.0f;
+      _n = 0;
+      return true;
+    }
     vocIndexEvent->voc_index = (float)_sgp40->measureVocIndex();
     return true;
   }
 
+  /*******************************************************************************/
+  /*!
+      @brief    Performs background sampling for the SGP40.
+                Runs once per second to accumulate raw and VOC index values
+                for later averaging in getEventRaw() and getEventVOCIndex().
+  */
+  /*******************************************************************************/
+  void fastTick() override {
+    if (!_sgp40) return;
+    if (!vocEnabled()) return;
+
+    uint32_t now = millis();
+    if (now - _lastFastMs >= 1000) {
+      _rawSum += _sgp40->measureRaw();
+      _vocSum += _sgp40->measureVocIndex();
+      _n++;
+      _lastFastMs = now;
+    }
+  }
+
 protected:
-  Adafruit_SGP40 *_sgp40; ///< SEN5X driver object
+  Adafruit_SGP40 *_sgp40; ///< SGP40
+  // background accumulation state
+  uint32_t _lastFastMs = 0;
+  uint32_t _n = 0;
+  float _vocSum = 0.0f;
+  uint32_t _rawSum = 0;
+
+  // enable fast sampling if either output is requested
+  inline bool vocEnabled() const {
+    return (getSensorVOCIndexPeriod() > 0) || (getSensorRawPeriod() > 0);
+  }
 };
 
-#endif // WipperSnapper_I2C_Driver_SEN5X
+#endif // WipperSnapper_I2C_Driver_SGP40_H

From 0b020d43e1c6b42d45b94a8cf3a9481c7fa672d2 Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Fri, 12 Sep 2025 13:40:35 -0700
Subject: [PATCH 02/17] removed override / const

---
 src/components/i2c/WipperSnapper_I2C.cpp                    | 2 +-
 src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h | 5 +++--
 src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h | 5 +++--
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/components/i2c/WipperSnapper_I2C.cpp b/src/components/i2c/WipperSnapper_I2C.cpp
index 73f6cbf21..0dbb4f264 100644
--- a/src/components/i2c/WipperSnapper_I2C.cpp
+++ b/src/components/i2c/WipperSnapper_I2C.cpp
@@ -1032,7 +1032,7 @@ bool WipperSnapper_Component_I2C::initI2CDevice(
     _drivers_out.push_back(_ssd1306);
     WS_DEBUG_PRINTLN("SSD1306 display initialized Successfully!");
   } else {
-    WS_DEBUG_PRINTLN("ERROR: I2C device type not found!")
+    WS_DEBUG_PRINTLN("ERROR: I2C device type not found!");
     _busStatusResponse =
         wippersnapper_i2c_v1_BusResponse_BUS_RESPONSE_UNSUPPORTED_SENSOR;
     return false;
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
index 2a4d5ff1e..349f031ed 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
@@ -46,7 +46,7 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
       @returns  True if initialized successfully, False otherwise.
   */
   /*******************************************************************************/
-  bool begin() override {
+  bool begin() {
     _sgp30 = new Adafruit_SGP30();
     if (!_sgp30->begin(_i2c)) {
       delete _sgp30;          // avoid leak on init failure
@@ -88,6 +88,7 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
   }
 
 protected:
+
   Adafruit_SGP30 *_sgp30; ///< Pointer to SGP30 sensor object
 
   // Fast sampling state
@@ -96,7 +97,7 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
   uint32_t _eco2Sum = 0;
   uint32_t _tvocSum = 0;
 
-  inline bool iaqEnabled() const {
+  inline bool iaqEnabled() {
     // Enable IAQ background reads if either metric is requested
     return (getSensorECO2Period() > 0) || (getSensorTVOCPeriod() > 0);
   }
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
index b615698bb..ae5383a36 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
@@ -63,7 +63,7 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
       @returns  True if initialized successfully, False otherwise.
   */
   /*******************************************************************************/
-  bool begin() override {
+  bool begin() {
     _sgp40 = new Adafruit_SGP40();
     if (!_sgp40 || !_sgp40->begin(_i2c)) {
       delete _sgp40;
@@ -142,6 +142,7 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
   }
 
 protected:
+
   Adafruit_SGP40 *_sgp40; ///< SGP40
   // background accumulation state
   uint32_t _lastFastMs = 0;
@@ -150,7 +151,7 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
   uint32_t _rawSum = 0;
 
   // enable fast sampling if either output is requested
-  inline bool vocEnabled() const {
+  inline bool vocEnabled() {
     return (getSensorVOCIndexPeriod() > 0) || (getSensorRawPeriod() > 0);
   }
 };

From f98d42b0775ea8985e4633d4b441c9581cacdb6f Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Fri, 12 Sep 2025 14:02:08 -0700
Subject: [PATCH 03/17] clang

---
 src/components/i2c/WipperSnapper_I2C.cpp      |  3 ++-
 .../i2c/drivers/WipperSnapper_I2C_Driver.h    | 10 ++++-----
 .../drivers/WipperSnapper_I2C_Driver_SGP30.h  | 21 +++++++++++--------
 .../drivers/WipperSnapper_I2C_Driver_SGP40.h  | 13 +++++++-----
 4 files changed, 27 insertions(+), 20 deletions(-)

diff --git a/src/components/i2c/WipperSnapper_I2C.cpp b/src/components/i2c/WipperSnapper_I2C.cpp
index 0dbb4f264..c4d969fd5 100644
--- a/src/components/i2c/WipperSnapper_I2C.cpp
+++ b/src/components/i2c/WipperSnapper_I2C.cpp
@@ -1349,7 +1349,8 @@ void WipperSnapper_Component_I2C::update() {
 
   // one fast pass for all drivers every update() call
   for (auto *drv : drivers) {
-    if (drv) drv->fastTick();
+    if (drv)
+      drv->fastTick();
   }
 
   long curTime;
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
index 109dbca5c..97e818ab4 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
@@ -57,9 +57,9 @@ class WipperSnapper_I2C_Driver {
   /*!
       @brief    Per-update background hook for drivers that need faster internal
                 sampling than the user publish interval.
-                Default is a no-op; override in concrete drivers (e.g., SGP30/40)
-                to maintain required ~1 Hz reads and accumulate/condition
-                values for later publish.
+                Default is a no-op; override in concrete drivers (e.g.,
+     SGP30/40) to maintain required ~1 Hz reads and accumulate/condition values
+     for later publish.
       @note     Call site: WipperSnapper_Component_I2C::update() will invoke
                 this once per loop for each driver. Implementations must be
                 non-blocking (do not delay); use millis()-based timing.
@@ -1413,8 +1413,8 @@ class WipperSnapper_I2C_Driver {
   long _ambientTempFPeriod = 0L; ///< The time period between reading the
                                  ///< ambient temp. (°F) sensor's value.
   long _ambientTempFPeriodPrv =
-      PERIOD_24HRS_AGO_MILLIS; ///< The time when the ambient temp. (°F) sensor
-                               ///< was last read.
+      PERIOD_24HRS_AGO_MILLIS;  ///< The time when the ambient temp. (°F) sensor
+                                ///< was last read.
   long _objectTempFPeriod = 0L; ///< The time period between reading the object
                                 ///< temp. (°F) sensor's value.
   long _objectTempFPeriodPrv =
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
index 349f031ed..1ad7cab4b 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
@@ -49,27 +49,31 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
   bool begin() {
     _sgp30 = new Adafruit_SGP30();
     if (!_sgp30->begin(_i2c)) {
-      delete _sgp30;          // avoid leak on init failure
+      delete _sgp30; // avoid leak on init failure
       _sgp30 = nullptr;
       return false;
     }
-    _sgp30->IAQinit();           // start IAQ algorithm
+    _sgp30->IAQinit();            // start IAQ algorithm
     _lastFastMs = millis();       // reset fast sampler
     _n = _eco2Sum = _tvocSum = 0; // clear accumulators
     return true;
   }
 
   bool getEventECO2(sensors_event_t *senseEvent) override {
-    if (!_sgp30) return false;
+    if (!_sgp30)
+      return false;
     bool ok = _sgp30->IAQmeasure();
-    if (ok) senseEvent->eCO2 = _sgp30->eCO2;
+    if (ok)
+      senseEvent->eCO2 = _sgp30->eCO2;
     return ok;
   }
 
   bool getEventTVOC(sensors_event_t *senseEvent) override {
-    if (!_sgp30) return false;
+    if (!_sgp30)
+      return false;
     bool ok = _sgp30->IAQmeasure();
-    if (ok) senseEvent->tvoc = _sgp30->TVOC;
+    if (ok)
+      senseEvent->tvoc = _sgp30->TVOC;
     return ok;
   }
 
@@ -79,8 +83,8 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
     uint32_t now = millis();
     if (now - _lastFastMs >= 1000) { // ~1 Hz cadence
       if (_sgp30 && _sgp30->IAQmeasure()) {
-        _eco2Sum += _sgp30->eCO2;   // uint16_t in library
-        _tvocSum += _sgp30->TVOC;   // uint16_t in library
+        _eco2Sum += _sgp30->eCO2; // uint16_t in library
+        _tvocSum += _sgp30->TVOC; // uint16_t in library
         _n++;
       }
       _lastFastMs = now;
@@ -88,7 +92,6 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
   }
 
 protected:
-
   Adafruit_SGP30 *_sgp30; ///< Pointer to SGP30 sensor object
 
   // Fast sampling state
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
index ae5383a36..92c1c10f1 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
@@ -87,7 +87,8 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
   */
   /*******************************************************************************/
   bool getEventRaw(sensors_event_t *rawEvent) override {
-    if (!_sgp40) return false;
+    if (!_sgp40)
+      return false;
     if (_n > 0) {
       rawEvent->data[0] = (float)_rawSum / (float)_n;
       _rawSum = 0;
@@ -109,7 +110,8 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
   */
   /*******************************************************************************/
   bool getEventVOCIndex(sensors_event_t *vocIndexEvent) override {
-    if (!_sgp40) return false;
+    if (!_sgp40)
+      return false;
     if (_n > 0) {
       vocIndexEvent->voc_index = _vocSum / (float)_n;
       _rawSum = 0;
@@ -129,8 +131,10 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
   */
   /*******************************************************************************/
   void fastTick() override {
-    if (!_sgp40) return;
-    if (!vocEnabled()) return;
+    if (!_sgp40)
+      return;
+    if (!vocEnabled())
+      return;
 
     uint32_t now = millis();
     if (now - _lastFastMs >= 1000) {
@@ -142,7 +146,6 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
   }
 
 protected:
-
   Adafruit_SGP40 *_sgp40; ///< SGP40
   // background accumulation state
   uint32_t _lastFastMs = 0;

From 662f61c3a786d6b07bd95cfbff723f31e84240a6 Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Fri, 12 Sep 2025 15:31:48 -0700
Subject: [PATCH 04/17] clang whitespace

---
 src/components/i2c/drivers/WipperSnapper_I2C_Driver.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
index 97e818ab4..1ff17134f 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
@@ -1413,8 +1413,8 @@ class WipperSnapper_I2C_Driver {
   long _ambientTempFPeriod = 0L; ///< The time period between reading the
                                  ///< ambient temp. (°F) sensor's value.
   long _ambientTempFPeriodPrv =
-      PERIOD_24HRS_AGO_MILLIS;  ///< The time when the ambient temp. (°F) sensor
-                                ///< was last read.
+      PERIOD_24HRS_AGO_MILLIS; ///< The time when the ambient temp. (°F) sensor
+                               ///< was last read.
   long _objectTempFPeriod = 0L; ///< The time period between reading the object
                                 ///< temp. (°F) sensor's value.
   long _objectTempFPeriodPrv =

From b1154e23a6eb692f570f1974049ab46d6dd1161c Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Sat, 13 Sep 2025 08:02:22 -0700
Subject: [PATCH 05/17] sgp30 doxygen

---
 .../i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h   | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
index 1ad7cab4b..da3354ce6 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
@@ -94,12 +94,24 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
 protected:
   Adafruit_SGP30 *_sgp30; ///< Pointer to SGP30 sensor object
 
-  // Fast sampling state
+  /** Millis timestamp of last 1 Hz background read. */
   uint32_t _lastFastMs = 0;
+
+  /** Number of samples accumulated since last publish. */
   uint32_t _n = 0;
+
+  /** Running sum of eCO2 samples for averaging. */
   uint32_t _eco2Sum = 0;
+
+  /** Running sum of TVOC samples for averaging. */
   uint32_t _tvocSum = 0;
 
+  /*******************************************************************************/
+  /*!
+      @brief  Returns whether IAQ background sampling should be active.
+      @return True if either eCO2 or TVOC metrics are configured to publish.
+  */
+  /*******************************************************************************/
   inline bool iaqEnabled() {
     // Enable IAQ background reads if either metric is requested
     return (getSensorECO2Period() > 0) || (getSensorTVOCPeriod() > 0);

From 5cbb3d55b8ddf31913a89eec8e96302302d9a7c4 Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Sat, 13 Sep 2025 08:19:48 -0700
Subject: [PATCH 06/17] sgp40 docs doxygen

---
 .../i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
index 92c1c10f1..4e2b135d7 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
@@ -147,13 +147,25 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
 
 protected:
   Adafruit_SGP40 *_sgp40; ///< SGP40
-  // background accumulation state
+
+  /** Millis timestamp of last 1 Hz background read. */
   uint32_t _lastFastMs = 0;
+
+  /** Number of samples accumulated since last publish. */
   uint32_t _n = 0;
+
+  /** Running sum of VOC index samples for averaging. */
   float _vocSum = 0.0f;
+
+  /** Running sum of raw samples for averaging. */
   uint32_t _rawSum = 0;
 
-  // enable fast sampling if either output is requested
+  /*******************************************************************************/
+  /*!
+      @brief  Returns whether VOC background sampling should be active.
+      @return True if either VOC Index or raw value is configured to publish.
+  */
+  /*******************************************************************************/
   inline bool vocEnabled() {
     return (getSensorVOCIndexPeriod() > 0) || (getSensorRawPeriod() > 0);
   }

From 281e41d687550f53266b2801c7c83cc3dfa85895 Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Sun, 14 Sep 2025 08:17:32 -0700
Subject: [PATCH 07/17] sgp30 / sgp40 integer values

also added sgp30 averaging option
---
 .../drivers/WipperSnapper_I2C_Driver_SGP30.h  | 38 ++++++++++++-------
 .../drivers/WipperSnapper_I2C_Driver_SGP40.h  |  4 +-
 2 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
index da3354ce6..b1b42cea6 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
@@ -59,23 +59,33 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
     return true;
   }
 
-  bool getEventECO2(sensors_event_t *senseEvent) override {
-    if (!_sgp30)
-      return false;
-    bool ok = _sgp30->IAQmeasure();
-    if (ok)
-      senseEvent->eCO2 = _sgp30->eCO2;
-    return ok;
+bool getEventECO2(sensors_event_t *senseEvent) override {
+  if (!_sgp30) return false;
+  if (_n > 0) {
+    senseEvent->eCO2 = (uint16_t)(_eco2Sum / _n);
+    _eco2Sum = 0; _tvocSum = 0; _n = 0;
+    return true;
+  }
+  if (_sgp30->IAQmeasure()) {
+    senseEvent->eCO2 = (uint16_t)_sgp30->eCO2;
+    return true;
   }
+  return false;
+}
 
-  bool getEventTVOC(sensors_event_t *senseEvent) override {
-    if (!_sgp30)
-      return false;
-    bool ok = _sgp30->IAQmeasure();
-    if (ok)
-      senseEvent->tvoc = _sgp30->TVOC;
-    return ok;
+bool getEventTVOC(sensors_event_t *senseEvent) override {
+  if (!_sgp30) return false;
+  if (_n > 0) {
+    senseEvent->tvoc = (uint16_t)(_tvocSum / _n);
+    _eco2Sum = 0; _tvocSum = 0; _n = 0;
+    return true;
+  }
+  if (_sgp30->IAQmeasure()) {
+    senseEvent->tvoc = (uint16_t)_sgp30->TVOC;
+    return true;
   }
+  return false;
+}
 
   void fastTick() override {
     if (!iaqEnabled())
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
index 4e2b135d7..6d64764e1 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
@@ -113,13 +113,13 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
     if (!_sgp40)
       return false;
     if (_n > 0) {
-      vocIndexEvent->voc_index = _vocSum / (float)_n;
+      vocIndexEvent->voc_index = (uint16_t)(_vocSum / (float)_n);
       _rawSum = 0;
       _vocSum = 0.0f;
       _n = 0;
       return true;
     }
-    vocIndexEvent->voc_index = (float)_sgp40->measureVocIndex();
+    vocIndexEvent->voc_index = (uint16_t)_sgp40->measureVocIndex();
     return true;
   }
 

From 222e45bc27af429bfe0f6510cb78951eec1c25bc Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Sun, 14 Sep 2025 08:45:12 -0700
Subject: [PATCH 08/17] style: apply clang-format to SGP30 driver

---
 .../drivers/WipperSnapper_I2C_Driver_SGP30.h  | 54 ++++++++++---------
 1 file changed, 30 insertions(+), 24 deletions(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
index b1b42cea6..19e011504 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
@@ -59,33 +59,39 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
     return true;
   }
 
-bool getEventECO2(sensors_event_t *senseEvent) override {
-  if (!_sgp30) return false;
-  if (_n > 0) {
-    senseEvent->eCO2 = (uint16_t)(_eco2Sum / _n);
-    _eco2Sum = 0; _tvocSum = 0; _n = 0;
-    return true;
-  }
-  if (_sgp30->IAQmeasure()) {
-    senseEvent->eCO2 = (uint16_t)_sgp30->eCO2;
-    return true;
+  bool getEventECO2(sensors_event_t *senseEvent) override {
+    if (!_sgp30)
+      return false;
+    if (_n > 0) {
+      senseEvent->eCO2 = (uint16_t)(_eco2Sum / _n);
+      _eco2Sum = 0;
+      _tvocSum = 0;
+      _n = 0;
+      return true;
+    }
+    if (_sgp30->IAQmeasure()) {
+      senseEvent->eCO2 = (uint16_t)_sgp30->eCO2;
+      return true;
+    }
+    return false;
   }
-  return false;
-}
 
-bool getEventTVOC(sensors_event_t *senseEvent) override {
-  if (!_sgp30) return false;
-  if (_n > 0) {
-    senseEvent->tvoc = (uint16_t)(_tvocSum / _n);
-    _eco2Sum = 0; _tvocSum = 0; _n = 0;
-    return true;
-  }
-  if (_sgp30->IAQmeasure()) {
-    senseEvent->tvoc = (uint16_t)_sgp30->TVOC;
-    return true;
+  bool getEventTVOC(sensors_event_t *senseEvent) override {
+    if (!_sgp30)
+      return false;
+    if (_n > 0) {
+      senseEvent->tvoc = (uint16_t)(_tvocSum / _n);
+      _eco2Sum = 0;
+      _tvocSum = 0;
+      _n = 0;
+      return true;
+    }
+    if (_sgp30->IAQmeasure()) {
+      senseEvent->tvoc = (uint16_t)_sgp30->TVOC;
+      return true;
+    }
+    return false;
   }
-  return false;
-}
 
   void fastTick() override {
     if (!iaqEnabled())

From 1dc39ca176308c7c2861c5207e439fffc2b93202 Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Thu, 25 Sep 2025 16:44:43 -0700
Subject: [PATCH 09/17] I2C: per-driver fastTick call site; fix fastTick docs;
 SGP30/SGP40: remove averaging, cache single reads; minor doc/guard fixes

---
 src/components/i2c/WipperSnapper_I2C.cpp      |  9 +-
 .../i2c/drivers/WipperSnapper_I2C_Driver.h    | 23 ++---
 .../drivers/WipperSnapper_I2C_Driver_SGP30.h  | 83 ++++++++-----------
 .../drivers/WipperSnapper_I2C_Driver_SGP40.h  | 53 +++---------
 4 files changed, 63 insertions(+), 105 deletions(-)

diff --git a/src/components/i2c/WipperSnapper_I2C.cpp b/src/components/i2c/WipperSnapper_I2C.cpp
index c4d969fd5..87582277b 100644
--- a/src/components/i2c/WipperSnapper_I2C.cpp
+++ b/src/components/i2c/WipperSnapper_I2C.cpp
@@ -1347,12 +1347,6 @@ void WipperSnapper_Component_I2C::update() {
   msgi2cResponse.which_payload =
       wippersnapper_signal_v1_I2CResponse_resp_i2c_device_event_tag;
 
-  // one fast pass for all drivers every update() call
-  for (auto *drv : drivers) {
-    if (drv)
-      drv->fastTick();
-  }
-
   long curTime;
   bool sensorsReturningFalse = true;
   int retries = 3;
@@ -1364,6 +1358,9 @@ void WipperSnapper_Component_I2C::update() {
 
     std::vector<WipperSnapper_I2C_Driver *>::iterator iter, end;
     for (iter = drivers.begin(), end = drivers.end(); iter != end; ++iter) {
+      // Per-driver fast tick (non-blocking)
+      (*iter)->fastTick();
+
       // Number of events which occurred for this driver
       msgi2cResponse.payload.resp_i2c_device_event.sensor_event_count = 0;
 
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
index 1ff17134f..4ea2869fd 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
@@ -34,7 +34,7 @@ class WipperSnapper_I2C_Driver {
 public:
   /*******************************************************************************/
   /*!
-      @brief    Instanctiates an I2C sensor.
+      @brief    Instantiates an I2C sensor.
       @param    i2c
                 The I2C hardware interface, default is Wire.
       @param    sensorAddress
@@ -55,14 +55,15 @@ class WipperSnapper_I2C_Driver {
 
   /*******************************************************************************/
   /*!
-      @brief    Per-update background hook for drivers that need faster internal
-                sampling than the user publish interval.
-                Default is a no-op; override in concrete drivers (e.g.,
-     SGP30/40) to maintain required ~1 Hz reads and accumulate/condition values
-     for later publish.
-      @note     Call site: WipperSnapper_Component_I2C::update() will invoke
-                this once per loop for each driver. Implementations must be
-                non-blocking (do not delay); use millis()-based timing.
+      @brief    Lightweight, per-update background hook for drivers that need
+                more frequent internal polling than the publish interval.
+                Default is a no-op; concrete drivers (e.g., SGP30/40) may
+                override this to perform a single non-blocking read and cache
+                results for later retrieval by getEvent*().
+      @note     Call site: WipperSnapper_Component_I2C::update() invokes this
+                once per loop for each driver. Implementations must be
+                non-blocking (do not delay); use millis()-based timing if
+                cadence is required.
   */
   /*******************************************************************************/
   virtual void fastTick() {}
@@ -1413,8 +1414,8 @@ class WipperSnapper_I2C_Driver {
   long _ambientTempFPeriod = 0L; ///< The time period between reading the
                                  ///< ambient temp. (°F) sensor's value.
   long _ambientTempFPeriodPrv =
-      PERIOD_24HRS_AGO_MILLIS; ///< The time when the ambient temp. (°F) sensor
-                               ///< was last read.
+      PERIOD_24HRS_AGO_MILLIS;  ///< The time when the ambient temp. (°F) sensor
+                                ///< was last read.
   long _objectTempFPeriod = 0L; ///< The time period between reading the object
                                 ///< temp. (°F) sensor's value.
   long _objectTempFPeriodPrv =
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
index 19e011504..4c82f36ae 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
@@ -33,7 +33,6 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
   */
   /*******************************************************************************/
   ~WipperSnapper_I2C_Driver_SGP30() override {
-    // Called when a SGP30 component is deleted.
     if (_sgp30) {
       delete _sgp30;
       _sgp30 = nullptr;
@@ -53,74 +52,62 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
       _sgp30 = nullptr;
       return false;
     }
-    _sgp30->IAQinit();            // start IAQ algorithm
-    _lastFastMs = millis();       // reset fast sampler
-    _n = _eco2Sum = _tvocSum = 0; // clear accumulators
+    _sgp30->IAQinit(); // start IAQ algorithm
+    _did_measure = false;
     return true;
   }
 
   bool getEventECO2(sensors_event_t *senseEvent) override {
     if (!_sgp30)
       return false;
-    if (_n > 0) {
-      senseEvent->eCO2 = (uint16_t)(_eco2Sum / _n);
-      _eco2Sum = 0;
-      _tvocSum = 0;
-      _n = 0;
-      return true;
+    if (!_did_measure) {
+      _did_measure = _sgp30->IAQmeasure();
     }
-    if (_sgp30->IAQmeasure()) {
-      senseEvent->eCO2 = (uint16_t)_sgp30->eCO2;
-      return true;
-    }
-    return false;
+    if (!_did_measure)
+      return false;
+
+    senseEvent->eCO2 = (uint16_t)_sgp30->eCO2;
+    _did_measure = false; // consume cached reading
+    return true;
   }
 
   bool getEventTVOC(sensors_event_t *senseEvent) override {
     if (!_sgp30)
       return false;
-    if (_n > 0) {
-      senseEvent->tvoc = (uint16_t)(_tvocSum / _n);
-      _eco2Sum = 0;
-      _tvocSum = 0;
-      _n = 0;
-      return true;
-    }
-    if (_sgp30->IAQmeasure()) {
-      senseEvent->tvoc = (uint16_t)_sgp30->TVOC;
-      return true;
+    if (!_did_measure) {
+      _did_measure = _sgp30->IAQmeasure();
     }
-    return false;
+    if (!_did_measure)
+      return false;
+
+    senseEvent->tvoc = (uint16_t)_sgp30->TVOC;
+    _did_measure = false; // consume cached reading
+    return true;
   }
 
+  /*******************************************************************************/
+  /*!
+      @brief  Performs a lightweight background poll for the SGP30.
+              Calls IAQmeasure() once and caches whether it succeeded.
+              Cached values (eCO2, TVOC) are then available via getEvent*().
+              No averaging or delay; must be non-blocking.
+  */
+  /*******************************************************************************/
   void fastTick() override {
+    if (!_sgp30)
+      return;
     if (!iaqEnabled())
-      return; // nothing enabled, save cycles
-    uint32_t now = millis();
-    if (now - _lastFastMs >= 1000) { // ~1 Hz cadence
-      if (_sgp30 && _sgp30->IAQmeasure()) {
-        _eco2Sum += _sgp30->eCO2; // uint16_t in library
-        _tvocSum += _sgp30->TVOC; // uint16_t in library
-        _n++;
-      }
-      _lastFastMs = now;
-    }
+      return;
+
+    // Only perform a single IAQ measurement and cache the result
+    _did_measure = _sgp30->IAQmeasure();
   }
 
 protected:
   Adafruit_SGP30 *_sgp30; ///< Pointer to SGP30 sensor object
 
-  /** Millis timestamp of last 1 Hz background read. */
-  uint32_t _lastFastMs = 0;
-
-  /** Number of samples accumulated since last publish. */
-  uint32_t _n = 0;
-
-  /** Running sum of eCO2 samples for averaging. */
-  uint32_t _eco2Sum = 0;
-
-  /** Running sum of TVOC samples for averaging. */
-  uint32_t _tvocSum = 0;
+  /** Whether we have a fresh IAQ measurement ready. */
+  bool _did_measure = false;
 
   /*******************************************************************************/
   /*!
@@ -134,4 +121,4 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
   }
 };
 
-#endif // WipperSnapper_I2C_Driver_SGP30
+#endif // WipperSnapper_I2C_Driver_SGP30_H
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
index 6d64764e1..66632a2cb 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
@@ -70,10 +70,9 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
       _sgp40 = nullptr;
       return false;
     }
-    _lastFastMs = millis();
-    _n = 0;
-    _vocSum = 0.0f;
-    _rawSum = 0;
+    // Initialize cached values
+    _rawValue = 0;
+    _vocIdx = 0;
     return true;
   }
 
@@ -89,14 +88,7 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
   bool getEventRaw(sensors_event_t *rawEvent) override {
     if (!_sgp40)
       return false;
-    if (_n > 0) {
-      rawEvent->data[0] = (float)_rawSum / (float)_n;
-      _rawSum = 0;
-      _vocSum = 0.0f;
-      _n = 0;
-      return true;
-    }
-    rawEvent->data[0] = (float)_sgp40->measureRaw();
+    rawEvent->data[0] = (float)_rawValue;
     return true;
   }
 
@@ -112,22 +104,15 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
   bool getEventVOCIndex(sensors_event_t *vocIndexEvent) override {
     if (!_sgp40)
       return false;
-    if (_n > 0) {
-      vocIndexEvent->voc_index = (uint16_t)(_vocSum / (float)_n);
-      _rawSum = 0;
-      _vocSum = 0.0f;
-      _n = 0;
-      return true;
-    }
-    vocIndexEvent->voc_index = (uint16_t)_sgp40->measureVocIndex();
+    vocIndexEvent->voc_index = (uint16_t)_vocIdx;
     return true;
   }
 
   /*******************************************************************************/
   /*!
       @brief    Performs background sampling for the SGP40.
-                Runs once per second to accumulate raw and VOC index values
-                for later averaging in getEventRaw() and getEventVOCIndex().
+                single poll (no averaging) and cache
+                results for getEventRaw()/getEventVOCIndex().
   */
   /*******************************************************************************/
   void fastTick() override {
@@ -136,29 +121,17 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
     if (!vocEnabled())
       return;
 
-    uint32_t now = millis();
-    if (now - _lastFastMs >= 1000) {
-      _rawSum += _sgp40->measureRaw();
-      _vocSum += _sgp40->measureVocIndex();
-      _n++;
-      _lastFastMs = now;
-    }
+    // Single poll and cache latest values (no cadence/averaging)
+    _rawValue = _sgp40->measureRaw();
+    _vocIdx = (uint16_t)_sgp40->measureVocIndex();
   }
 
 protected:
   Adafruit_SGP40 *_sgp40; ///< SGP40
 
-  /** Millis timestamp of last 1 Hz background read. */
-  uint32_t _lastFastMs = 0;
-
-  /** Number of samples accumulated since last publish. */
-  uint32_t _n = 0;
-
-  /** Running sum of VOC index samples for averaging. */
-  float _vocSum = 0.0f;
-
-  /** Running sum of raw samples for averaging. */
-  uint32_t _rawSum = 0;
+  /** Cached latest measurements (no averaging). */
+  uint16_t _rawValue = 0;
+  uint16_t _vocIdx = 0;
 
   /*******************************************************************************/
   /*!

From fe0ca83d47dbadeacca2958961f0ad71c62e16fc Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Thu, 25 Sep 2025 17:04:39 -0700
Subject: [PATCH 10/17] clang format

---
 src/components/i2c/drivers/WipperSnapper_I2C_Driver.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
index 4ea2869fd..96f683cd4 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
@@ -1414,8 +1414,8 @@ class WipperSnapper_I2C_Driver {
   long _ambientTempFPeriod = 0L; ///< The time period between reading the
                                  ///< ambient temp. (°F) sensor's value.
   long _ambientTempFPeriodPrv =
-      PERIOD_24HRS_AGO_MILLIS;  ///< The time when the ambient temp. (°F) sensor
-                                ///< was last read.
+      PERIOD_24HRS_AGO_MILLIS; ///< The time when the ambient temp. (°F) sensor
+                               ///< was last read.
   long _objectTempFPeriod = 0L; ///< The time period between reading the object
                                 ///< temp. (°F) sensor's value.
   long _objectTempFPeriodPrv =

From f9dbb5e5bdc670e384517b6f4b10cac2bfc33f38 Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Thu, 25 Sep 2025 17:27:44 -0700
Subject: [PATCH 11/17] docs: add Doxygen comment for _vocIdx in SGP40 driver

---
 src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
index 66632a2cb..ed6488349 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
@@ -131,7 +131,7 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
 
   /** Cached latest measurements (no averaging). */
   uint16_t _rawValue = 0;
-  uint16_t _vocIdx = 0;
+  uint16_t _vocIdx = 0; ///< Index for the VOC (volatile organic compounds) sensor reading
 
   /*******************************************************************************/
   /*!

From 557a0f43e4c0fae4ca732ca43dff3d0623022d87 Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Thu, 25 Sep 2025 17:41:47 -0700
Subject: [PATCH 12/17] docs: concise VOC index comment

---
 src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
index ed6488349..084a8f145 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
@@ -131,7 +131,7 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
 
   /** Cached latest measurements (no averaging). */
   uint16_t _rawValue = 0;
-  uint16_t _vocIdx = 0; ///< Index for the VOC (volatile organic compounds) sensor reading
+  uint16_t _vocIdx = 0; ///< VOC index value (0–500)
 
   /*******************************************************************************/
   /*!

From 0a0927dd0c7b900033efeccfadcda13c6eace6db Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Fri, 26 Sep 2025 17:39:28 -0700
Subject: [PATCH 13/17] SGP30/40: add fastTick 1Hz cadence, simplify caching,
 update docs

---
 .../i2c/drivers/WipperSnapper_I2C_Driver.h    |  4 +-
 .../drivers/WipperSnapper_I2C_Driver_SGP30.h  | 33 +++++++++++---
 .../drivers/WipperSnapper_I2C_Driver_SGP40.h  | 43 ++++++++++++++-----
 3 files changed, 62 insertions(+), 18 deletions(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
index 96f683cd4..4ea2869fd 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
@@ -1414,8 +1414,8 @@ class WipperSnapper_I2C_Driver {
   long _ambientTempFPeriod = 0L; ///< The time period between reading the
                                  ///< ambient temp. (°F) sensor's value.
   long _ambientTempFPeriodPrv =
-      PERIOD_24HRS_AGO_MILLIS; ///< The time when the ambient temp. (°F) sensor
-                               ///< was last read.
+      PERIOD_24HRS_AGO_MILLIS;  ///< The time when the ambient temp. (°F) sensor
+                                ///< was last read.
   long _objectTempFPeriod = 0L; ///< The time period between reading the object
                                 ///< temp. (°F) sensor's value.
   long _objectTempFPeriodPrv =
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
index 4c82f36ae..b71672afb 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
@@ -4,6 +4,8 @@
 #include "WipperSnapper_I2C_Driver.h"
 #include <Adafruit_SGP30.h>
 
+#define SGP30_FASTTICK_INTERVAL_MS 1000 ///< Enforce ~1 Hz cadence
+
 /**************************************************************************/
 /*!
     @brief  Class that provides a driver interface for a SGP30 sensor.
@@ -54,6 +56,7 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
     }
     _sgp30->IAQinit(); // start IAQ algorithm
     _did_measure = false;
+    _lastFastMs = millis() - SGP30_FASTTICK_INTERVAL_MS;
     return true;
   }
 
@@ -87,10 +90,22 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
 
   /*******************************************************************************/
   /*!
-      @brief  Performs a lightweight background poll for the SGP30.
-              Calls IAQmeasure() once and caches whether it succeeded.
-              Cached values (eCO2, TVOC) are then available via getEvent*().
-              No averaging or delay; must be non-blocking.
+      @brief  Performs background sampling for the SGP30.
+
+              This method enforces a ~1 Hz cadence recommended by the sensor
+              datasheet. On each call, it checks the elapsed time since the
+              last poll using `millis()`. If at least
+              SGP30_FASTTICK_INTERVAL_MS have passed, it performs a single
+              IAQ measurement and caches the result in `_did_measure`.
+
+              Cached values (eCO2, TVOC) are later returned by
+              `getEventECO2()` and `getEventTVOC()` without re-triggering I2C
+              traffic.
+
+      @note   Called automatically from
+              `WipperSnapper_Component_I2C::update()` once per loop iteration.
+              Must be non-blocking (no delays). The millis-based guard ensures
+              the sensor is not over-polled.
   */
   /*******************************************************************************/
   void fastTick() override {
@@ -99,8 +114,11 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
     if (!iaqEnabled())
       return;
 
-    // Only perform a single IAQ measurement and cache the result
-    _did_measure = _sgp30->IAQmeasure();
+    uint32_t now = millis();
+    if (now - _lastFastMs >= SGP30_FASTTICK_INTERVAL_MS) {
+      _did_measure = _sgp30->IAQmeasure();
+      _lastFastMs = now;
+    }
   }
 
 protected:
@@ -109,6 +127,9 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
   /** Whether we have a fresh IAQ measurement ready. */
   bool _did_measure = false;
 
+  /** Timestamp of last poll to enforce 1 Hz cadence. */
+  uint32_t _lastFastMs = 0;
+
   /*******************************************************************************/
   /*!
       @brief  Returns whether IAQ background sampling should be active.
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
index 084a8f145..2001836f3 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
@@ -20,6 +20,8 @@
 #include <Adafruit_SGP40.h>
 #include <Wire.h>
 
+#define SGP40_FASTTICK_INTERVAL_MS 1000 ///< Enforce ~1 Hz cadence
+
 /**************************************************************************/
 /*!
     @brief  Class that provides a driver interface for the SGP40 sensor.
@@ -73,6 +75,7 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
     // Initialize cached values
     _rawValue = 0;
     _vocIdx = 0;
+    _lastFastMs = millis() - SGP40_FASTTICK_INTERVAL_MS;
     return true;
   }
 
@@ -110,9 +113,21 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
 
   /*******************************************************************************/
   /*!
-      @brief    Performs background sampling for the SGP40.
-                single poll (no averaging) and cache
-                results for getEventRaw()/getEventVOCIndex().
+      @brief  Performs background sampling for the SGP40.
+
+              This method enforces a ~1 Hz cadence recommended by the sensor
+              datasheet. On each call, it checks the elapsed time since the last
+              poll using `millis()`. If at least SGP40_FASTTICK_INTERVAL_MS ms
+              have passed, it reads a new raw value and VOC index from the
+     sensor and caches them in `_rawValue` and `_vocIdx`.
+
+              Cached results are later returned by `getEventRaw()` and
+              `getEventVOCIndex()` without re-triggering I2C traffic.
+
+      @note   Called automatically from
+              `WipperSnapper_Component_I2C::update()` once per loop iteration.
+              Must be non-blocking (no delays). The millis-based guard ensures
+              the sensor is not over-polled.
   */
   /*******************************************************************************/
   void fastTick() override {
@@ -121,17 +136,25 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
     if (!vocEnabled())
       return;
 
-    // Single poll and cache latest values (no cadence/averaging)
-    _rawValue = _sgp40->measureRaw();
-    _vocIdx = (uint16_t)_sgp40->measureVocIndex();
+    uint32_t now = millis();
+    if (now - _lastFastMs >= SGP40_FASTTICK_INTERVAL_MS) {
+      _rawValue = _sgp40->measureRaw();
+      _vocIdx = (int32_t)_sgp40->measureVocIndex();
+      _lastFastMs = now;
+    }
   }
 
 protected:
-  Adafruit_SGP40 *_sgp40; ///< SGP40
+  Adafruit_SGP40 *_sgp40; ///< Pointer to SGP40 sensor object
 
-  /** Cached latest measurements (no averaging). */
-  uint16_t _rawValue = 0;
-  uint16_t _vocIdx = 0; ///< VOC index value (0–500)
+  /**
+   * Cached latest measurements from the sensor.
+   * - _rawValue: raw sensor output (ticks)
+   * - _vocIdx: VOC Index (signed, per datasheet)
+   */
+  uint16_t _rawValue = 0;   ///< Raw sensor output (ticks)
+  int32_t _vocIdx = 0;      ///< VOC Index (signed, per datasheet)
+  uint32_t _lastFastMs = 0; ///< Last poll timestamp to enforce 1 Hz cadence
 
   /*******************************************************************************/
   /*!

From 7e6e75c7395d0220684cc977d9bc3b2d04a0268c Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Fri, 26 Sep 2025 17:57:01 -0700
Subject: [PATCH 14/17] clang whitespace

---
 src/components/i2c/drivers/WipperSnapper_I2C_Driver.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
index 4ea2869fd..96f683cd4 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver.h
@@ -1414,8 +1414,8 @@ class WipperSnapper_I2C_Driver {
   long _ambientTempFPeriod = 0L; ///< The time period between reading the
                                  ///< ambient temp. (°F) sensor's value.
   long _ambientTempFPeriodPrv =
-      PERIOD_24HRS_AGO_MILLIS;  ///< The time when the ambient temp. (°F) sensor
-                                ///< was last read.
+      PERIOD_24HRS_AGO_MILLIS; ///< The time when the ambient temp. (°F) sensor
+                               ///< was last read.
   long _objectTempFPeriod = 0L; ///< The time period between reading the object
                                 ///< temp. (°F) sensor's value.
   long _objectTempFPeriodPrv =

From 7f7f4ddaee37bd13ec9cba7de4ae5796118b3c09 Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Mon, 29 Sep 2025 08:03:30 -0700
Subject: [PATCH 15/17] remove override on sgp30/sgp40 destructors

---
 src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h | 2 +-
 src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
index b71672afb..ef696b0e3 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
@@ -34,7 +34,7 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
       @brief    Destructor for an SGP30 sensor.
   */
   /*******************************************************************************/
-  ~WipperSnapper_I2C_Driver_SGP30() override {
+  ~WipperSnapper_I2C_Driver_SGP30() {
     if (_sgp30) {
       delete _sgp30;
       _sgp30 = nullptr;
diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
index 2001836f3..a31d4807e 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP40.h
@@ -52,7 +52,7 @@ class WipperSnapper_I2C_Driver_SGP40 : public WipperSnapper_I2C_Driver {
                 when the driver is destroyed.
   */
   /*******************************************************************************/
-  ~WipperSnapper_I2C_Driver_SGP40() override {
+  ~WipperSnapper_I2C_Driver_SGP40() {
     if (_sgp40) {
       delete _sgp40;
       _sgp40 = nullptr;

From ed2fe6715d838f92004ed77348e37691ceda97a0 Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Tue, 30 Sep 2025 11:00:56 -0700
Subject: [PATCH 16/17] sgp30 fastTick only, remove consume cache confusion

---
 .../drivers/WipperSnapper_I2C_Driver_SGP30.h  | 70 ++++++++++++-------
 1 file changed, 46 insertions(+), 24 deletions(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
index ef696b0e3..56500fc2a 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
@@ -55,36 +55,55 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
       return false;
     }
     _sgp30->IAQinit(); // start IAQ algorithm
-    _did_measure = false;
+
+    // Initialize cached values and cadence
+    _eco2 = 0;
+    _tvoc = 0;
     _lastFastMs = millis() - SGP30_FASTTICK_INTERVAL_MS;
     return true;
   }
 
+/*******************************************************************************/
+/*!
+    @brief    Gets the most recently cached eCO2 reading.
+
+              This value is updated in `fastTick()` at a ~1 Hz cadence
+              and returned directly here without re-triggering an I2C
+              transaction.
+
+    @param    senseEvent
+              Pointer to an Adafruit Sensor event that will be populated
+              with the cached eCO2 value (in ppm).
+
+    @returns  True if a cached value is available, False otherwise.
+*/
+/*******************************************************************************/
   bool getEventECO2(sensors_event_t *senseEvent) override {
     if (!_sgp30)
       return false;
-    if (!_did_measure) {
-      _did_measure = _sgp30->IAQmeasure();
-    }
-    if (!_did_measure)
-      return false;
-
-    senseEvent->eCO2 = (uint16_t)_sgp30->eCO2;
-    _did_measure = false; // consume cached reading
+    senseEvent->eCO2 = _eco2;
     return true;
   }
 
+/*******************************************************************************/
+/*!
+    @brief    Gets the most recently cached TVOC reading.
+
+              This value is updated in `fastTick()` at a ~1 Hz cadence
+              and returned directly here without re-triggering an I2C
+              transaction.
+
+    @param    senseEvent
+              Pointer to an Adafruit Sensor event that will be populated
+              with the cached TVOC value (in ppb).
+
+    @returns  True if a cached value is available, False otherwise.
+*/
+/*******************************************************************************/
   bool getEventTVOC(sensors_event_t *senseEvent) override {
     if (!_sgp30)
       return false;
-    if (!_did_measure) {
-      _did_measure = _sgp30->IAQmeasure();
-    }
-    if (!_did_measure)
-      return false;
-
-    senseEvent->tvoc = (uint16_t)_sgp30->TVOC;
-    _did_measure = false; // consume cached reading
+    senseEvent->tvoc = _tvoc;
     return true;
   }
 
@@ -96,11 +115,10 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
               datasheet. On each call, it checks the elapsed time since the
               last poll using `millis()`. If at least
               SGP30_FASTTICK_INTERVAL_MS have passed, it performs a single
-              IAQ measurement and caches the result in `_did_measure`.
+              IAQ measurement and caches the results in `_eco2` and `_tvoc`.
 
-              Cached values (eCO2, TVOC) are later returned by
-              `getEventECO2()` and `getEventTVOC()` without re-triggering I2C
-              traffic.
+              Cached values are then returned by `getEventECO2()` and
+              `getEventTVOC()` without re-triggering I2C traffic.
 
       @note   Called automatically from
               `WipperSnapper_Component_I2C::update()` once per loop iteration.
@@ -116,7 +134,10 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
 
     uint32_t now = millis();
     if (now - _lastFastMs >= SGP30_FASTTICK_INTERVAL_MS) {
-      _did_measure = _sgp30->IAQmeasure();
+      if (_sgp30->IAQmeasure()) {
+        _eco2 = (uint16_t)_sgp30->eCO2;
+        _tvoc = (uint16_t)_sgp30->TVOC;
+      }
       _lastFastMs = now;
     }
   }
@@ -124,8 +145,9 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
 protected:
   Adafruit_SGP30 *_sgp30; ///< Pointer to SGP30 sensor object
 
-  /** Whether we have a fresh IAQ measurement ready. */
-  bool _did_measure = false;
+  /** Cached latest measurements (no averaging). */
+  uint16_t _eco2 = 0; ///< eCO2, in ppm
+  uint16_t _tvoc = 0; ///< TVOC, in ppb
 
   /** Timestamp of last poll to enforce 1 Hz cadence. */
   uint32_t _lastFastMs = 0;

From a0fdee7f2755b0c936dfba52c19f76c460195889 Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Tue, 30 Sep 2025 12:22:33 -0700
Subject: [PATCH 17/17] SGP30: align Doxygen / clang

---
 .../drivers/WipperSnapper_I2C_Driver_SGP30.h  | 48 +++++++++----------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
index 56500fc2a..4c283a840 100644
--- a/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
+++ b/src/components/i2c/drivers/WipperSnapper_I2C_Driver_SGP30.h
@@ -63,21 +63,21 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
     return true;
   }
 
-/*******************************************************************************/
-/*!
-    @brief    Gets the most recently cached eCO2 reading.
+  /*******************************************************************************/
+  /*!
+      @brief    Gets the most recently cached eCO2 reading.
 
-              This value is updated in `fastTick()` at a ~1 Hz cadence
-              and returned directly here without re-triggering an I2C
-              transaction.
+                This value is updated in `fastTick()` at a ~1 Hz cadence
+                and returned directly here without re-triggering an I2C
+                transaction.
 
-    @param    senseEvent
-              Pointer to an Adafruit Sensor event that will be populated
-              with the cached eCO2 value (in ppm).
+      @param    senseEvent
+                Pointer to an Adafruit_Sensor event that will be populated
+                with the cached eCO2 value (in ppm).
 
-    @returns  True if a cached value is available, False otherwise.
-*/
-/*******************************************************************************/
+      @returns  True if a cached value is available, False otherwise.
+  */
+  /*******************************************************************************/
   bool getEventECO2(sensors_event_t *senseEvent) override {
     if (!_sgp30)
       return false;
@@ -85,21 +85,21 @@ class WipperSnapper_I2C_Driver_SGP30 : public WipperSnapper_I2C_Driver {
     return true;
   }
 
-/*******************************************************************************/
-/*!
-    @brief    Gets the most recently cached TVOC reading.
+  /*******************************************************************************/
+  /*!
+      @brief    Gets the most recently cached TVOC reading.
 
-              This value is updated in `fastTick()` at a ~1 Hz cadence
-              and returned directly here without re-triggering an I2C
-              transaction.
+                This value is updated in `fastTick()` at a ~1 Hz cadence
+                and returned directly here without re-triggering an I2C
+                transaction.
 
-    @param    senseEvent
-              Pointer to an Adafruit Sensor event that will be populated
-              with the cached TVOC value (in ppb).
+      @param    senseEvent
+                Pointer to an Adafruit_Sensor event that will be populated
+                with the cached TVOC value (in ppb).
 
-    @returns  True if a cached value is available, False otherwise.
-*/
-/*******************************************************************************/
+      @returns  True if a cached value is available, False otherwise.
+  */
+  /*******************************************************************************/
   bool getEventTVOC(sensors_event_t *senseEvent) override {
     if (!_sgp30)
       return false;