Merge pull request #13 from fgallaire/master

Fix #9

Author: kattni

README.rst

@@ -26,9 +26,6 @@ Please ensure all dependencies are available on the CircuitPython filesystem.
 This is easily achieved by downloading
 `the Adafruit library and driver bundle <https://github.com/adafruit/Adafruit_CircuitPython_Bundle>`_.
 
-**NOTE:** This library is not supported for smaller non-Express boards like
-the Trinket M0, Gemma M0, etc.
-
 Installing from PyPI
 ====================
 

adafruit_thermal_printer/thermal_printer.py

@@ -202,7 +202,7 @@ def _write_char(self, char):
         if char == '\r':
             return  # Strip carriage returns by skipping them.
         self._wait_timeout()
-        self._uart.write(char.encode('ascii'))
+        self._uart.write(bytes(char, 'ascii'))
         delay = self._byte_delay_s
         # Add extra delay for newlines or moving past the last column.
         if char == '\n' or self._column == self._max_column:
@@ -238,7 +238,7 @@ def _unset_print_mode(self, mask):
 
     def send_command(self, command):
         """Send a command string to the printer."""
-        self._uart.write(command.encode('ascii'))
+        self._uart.write(bytes(command, 'ascii'))
 
     # Do initialization in warm_up instead of the initializer because this
     # initialization takes a long time (5 seconds) and shouldn't happen during