add a method byte_to_bits

Author: benoitguigal

epson_printer/__init__.py

@@ -1,5 +1,5 @@
 
-__version__ = "1.10.0"
+__version__ = "1.11.0"
 
 __all__ = ["epsonprinter","testpage"]
 

epson_printer/epsonprinter.py

@@ -2,8 +2,8 @@
 from contextlib import contextmanager
 import usb.core
 import usb.util
-import time
 
+from .utils import to_hex, byte_to_bits
 
 
 ESC = 27
@@ -148,7 +148,7 @@ def in_endpoint_match(ep):
 
 
     def write_bytes(self, byte_array, timeout=5000):
-        msg = ''.join([chr(b) for b in byte_array])
+        msg = to_hex(byte_array)
         self.write(msg, timeout)
 
     def write(self, msg, timeout=5000):
@@ -247,7 +247,8 @@ def paper_present(self):
             self.transmit_real_time_status(4)
             with time_limit(1):
                 data = self.blocking_read()
-                return data == 18
+                bits = byte_to_bits(data)
+                return bits[5] == 0
         except:
             return False
 

epson_printer/utils.py

@@ -0,0 +1,22 @@
+import math
+
+
+def to_hex(arr):
+    """ convert a decimal array to an hexadecimal String"""
+    return ''.join(chr(b) for b in arr)
+
+
+def byte_to_bits(b):
+
+    assert b <= 255
+
+    r = b
+
+    bits = {}
+
+    for i in range(0, 8):
+        a = math.pow(2, 7 - i)
+        bits[7 - i] = int(r // a)
+        r = r % a
+
+    return bits