Remove sleep/wake, causes junk on first print. Use offline/online instead. Update simple demo.

Author: tdicola

adafruit_thermal_printer/thermal_printer.py

@@ -208,8 +208,7 @@ def _unset_print_mode(self, mask):
 
     def send_command(self, command):
         """Send a command string to the printer."""
-        for char in command:
-            self._write_char(char)
+        self._uart.write(command)
 
     # Do initialization in begin instead of the initializer because this
     # initialization takes a long time (5 seconds) and shouldn't happen during
@@ -223,7 +222,6 @@ def begin(self, heat_time=120):
         """
         assert 0 <= heat_time <= 255
         self._set_timeout(0.5)  # Half second delay for printer to initialize.
-        self.wake()
         self.reset()
         # ESC 7 n1 n2 n3 Setting Control Parameter Command
         # n1 = "max heating dots" 0-255 -- max number of thermal print head
@@ -242,9 +240,8 @@ def begin(self, heat_time=120):
         # More heating time = darker print, but slower printing speed and
         # possibly paper 'stiction'.  More heating interval = clearer print,
         # but slower printing speed.
-        self.send_command('\x1B7')  # ESC + '7' (print settings)
-        # Send heating dots, heat time, heat interval.
-        self.send_command('\x0B{0}\x28'.format(chr(heat_time)))
+        # Send ESC + '7' (print settings) + heating dots, heat time, heat interval.
+        self.send_command('\x1B7\x0B{0}\x28'.format(chr(heat_time)))
         # Print density description from manual:
         # DC2 # n Set printing density
         # D4..D0 of n is used to set the printing density.  Density is
@@ -265,15 +262,21 @@ def reset(self):
         self._max_column = 32
         self._char_height = 24
         self._line_spacing = 6
+        self._barcode_height = 50
+        # Configure tab stops on recent printers.
+        # ESC + 'D' + tab stop value list ending with null to terminate.
+        self.send_command('\x1BD\x04\x08\x10\x14\x18\x1C\x00')
+
 
     def print(self, text, end='\n'):
         """Print a line of text.  Optionally specify the end keyword to
         override the new line printed after the text (set to None to disable
         the new line entirely).
         """
-        self.send_command(text)
+        for char in text:
+            self._write_char(char)
         if end is not None:
-            self.send_command(end)
+            self._write_char(end)
 
     def print_barcode(self, text, barcode_type):
         """Print a barcode with the specified text/number (the meaning
@@ -451,24 +454,6 @@ def online(self):
         """
         self.send_command('\x1B=\x01')  # ESC + '=' + 1
 
-    def sleep_after(self, seconds):
-        """Put the printer into sleep mode after the specified number of
-        seconds (0-65535).  Must call wake to wake up and send commands
-        afterwards!
-        """
-        assert 0 <= seconds <= 65535
-        low_byte = seconds & 0xFF
-        high_byte = (seconds >> 8) & 0xFF
-        self.send_command('\x1B8{0}{1}'.format(chr(low_byte), chr(high_byte)))
-
-    def wake(self):
-        """Wake the thermal printer into an online state ready to receive
-        commands.
-        """
-        self.send_command('\xFF')  # Wake command.
-        time.sleep(0.050)
-        self.send_command('\x1B8\x00\x00')  # Sleep off
-
     def has_paper(self):
         """Return a boolean indicating if the printer has paper.  You MUST have
         the serial RX line hooked up for this to work.  NOTE: be VERY CAREFUL

adafruit_thermal_printer/thermal_printer_legacy.py

@@ -108,28 +108,6 @@ def print_barcode(self, text, barcode_type):
         self._set_timeout((self._barcode_height + 40) * self._dot_print_s)
         self._column = 0
 
-    def wake(self):
-        """Wake the thermal printer into an online state ready to receive
-        commands.
-        """
-        self.send_command('\xFF')  # Wake command.
-        # Datasheet recommends a 50 mS delay before issuing further commands,
-        # but in practice this alone isn't sufficient (e.g. text size/style
-        # commands may still be misinterpreted on wake).  A slightly longer
-        # delay, interspersed with NUL chars (no-ops) seems to help.
-        for _ in range(10):
-            self.send_command('\x00')
-            self._set_timeout(0.01)
-
-    def sleep_after(self, seconds):
-        """Put the printer into sleep mode after the specified number of
-        seconds (0-255).  Must call wake to wake up and send commands
-        afterwards!
-        """
-        # Firmware before 2.64 uses an 8-bit number of seconds instead of 16-bit.
-        assert 0 <= seconds <= 255
-        self.send_command('\x1B8{0}'.format(chr(seconds)))
-
     def reset(self):
         """Reset the printer."""
         # Issue a reset command to the printer. (ESC + @)
@@ -139,6 +117,7 @@ def reset(self):
         self._max_column = 32
         self._char_height = 24
         self._line_spacing = 6
+        self._barcode_height = 50
         # Skip tab configuration on older printers.
 
     def feed(self, lines):

examples/simpletest.py

@@ -24,8 +24,8 @@
 
 # Create a serial connection for the printer.  You must use the same baud rate
 # as your printer is configured (print a test page by holding the button
-# during power-up and it will show the baud rate).  Most printers use 119200.
-uart = busio.UART(TX, RX, baudrate=119200)
+# during power-up and it will show the baud rate).  Most printers use 19200.
+uart = busio.UART(TX, RX, baudrate=19200)
 
 # Create the printer instance.
 printer = thermal_printer.ThermalPrinter(uart)
@@ -35,6 +35,13 @@
 # automatically in the initializer above).
 printer.begin()
 
+# Check if the printer has paper.  This only works if the RX line is connected
+# on your board (but BE CAREFUL as mentioned above this RX line is 5V!)
+if printer.has_paper():
+    print('Printer has paper!')
+else:
+    print('Printer might be out of paper, or RX is disconnected!')
+
 # Print a test page:
 printer.test_page()
 
@@ -44,5 +51,61 @@
 # Print a line of text:
 printer.print('Hello world!')
 
-# Move the paper forward two lines:
+# Print a bold line of text:
+printer.bold = True
+printer.print('Bold hello world!')
+printer.bold = False
+
+# Print a normal/thin underline line of text:
+printer.underline_thin()
+printer.print('Thin underline!')
+
+# Print a thick underline line of text:
+printer.underline_thick()
+printer.print('Thick underline!')
+
+# Disable underlines.
+printer.underline_off()
+
+# Print an inverted line.
+printer.inverse = True
+printer.print('Inverse hello world!')
+printer.inverse = False
+
+# Print an upside down line.
+printer.upside_down = True
+printer.print('Upside down hello!')
+printer.upside_down = False
+
+# Print a double height line.
+printer.double_height = True
+printer.print('Double height!')
+printer.double_height = False
+
+# Print a double width line.
+printer.double_width = True
+printer.print('Double width!')
+printer.double_width = False
+
+# Print a strike-through line.
+printer.strike = True
+printer.print('Strike-through hello!')
+printer.strike = False
+
+# Print medium size text.
+printer.set_size_medium()
+printer.print('Medium size text!')
+
+# Print large size text.
+printer.set_size_large()
+printer.print('Large size text!')
+
+# Back to normal / small size text.
+printer.set_size_small()
+
+# Print a UPC barcode.
+printer.print('UPCA barcode:')
+printer.print_barcode('123456789012', printer.UPC_A)
+
+# Feed a few lines to see everything.
 printer.feed(2)