Initial commit

arduinoserialhal.py

@@ -0,0 +1,132 @@
+#!/usr/bin/env python
+#
+# This code is running on the host and implements the serial protocol
+# used to control the display connected to the MCU.
+#
+# On the MCU side, the serial protocol is either implemented under Arduino
+# or under MicroPython.
+#
+import serial
+
+class ArduinoSerialHAL:
+	"""
+	ArduinoSerialHAL is handles the serial protocol (API) used to control
+	the display connected to the MCU.
+	"""
+
+	def __init__(self, config):
+		self.port = config['port']
+		self.baudrate = config['baudrate']
+		self.ser = None  # initialized in reset()
+		self.reset()
+
+	def readline(self):
+		"""
+		Read output from MCU over the serial link
+		"""
+		if not self.ser.in_waiting:
+			return None
+		line = self.ser.readline()
+		return line
+
+	def reset(self):
+		"""
+		(Re-)open serial ports and resynchronize the protocol
+		"""
+		if self.ser:
+			print('SerialProtocol: closing serial link')
+			self.ser.close()
+		print('SerialProtocol: opening port {} @ {} baud'.format(self.port, self.baudrate))
+		self.ser = serial.Serial(self.port, baudrate=self.baudrate, rtscts=True, timeout=0.1, write_timeout=0.5)
+		self.resynchronize_protocol()
+
+	def resynchronize_protocol(self):
+		"""
+		Resynchronize the protocol by writing a string of zeroes.
+		"""
+		data = bytearray(10)
+		self.ser.write(data)
+
+	def safe_write(self, data):
+		"""
+		Write data to the serial link and attempt to handle write timeouts
+		"""
+		try:
+			self.ser.write(data)
+			return
+		except serial.SerialTimeoutException:
+			print('SerialProtocol: write timeout, attempting reset..')
+			print('WARN: Serial write timed out, attempting reset')
+			self.reset()
+			print('SerialProtocol: retrying send of {} bytes'.format(len(data)))
+			self.ser.write(data)
+
+	def init_display(self, num_pixels=256):
+		# Setup FastLED library
+		data = bytearray(3)
+		data[0] = ord('i')
+		data[1] = num_pixels & 0xff
+		data[2] = (num_pixels >> 8) & 0xff
+		self.safe_write(data)
+
+	def clear_display(self):
+		data = bytearray(2)
+		data[0] = ord('c')
+		self.safe_write(data)
+
+	def update_display(self, num_modified_pixels=None):
+		data = bytearray(2)
+		data[0] = ord('s')
+		self.safe_write(data)
+
+	def put_pixel(self, addr, r, g, b):
+		data = bytearray(6)
+		data[0] = ord('l')
+		data[1] = (addr >> 0) & 0xff
+		data[2] = (addr >> 8) & 0xff
+		data[3] = r
+		data[4] = g
+		data[5] = b
+		self.safe_write(data)
+
+	def set_rtc(self, t):
+		# Resynchronize RTC
+		data = bytearray(5)
+		data[0] = ord('@')
+		t = int(t)
+		data[1] = (t >> 0) & 0xff
+		data[2] = (t >> 8) & 0xff
+		data[3] = (t >> 16) & 0xff
+		data[4] = (t >> 24) & 0xff
+		self.safe_write(data)
+
+	def set_auto_time(self, enable=True):
+		# Enable or disable automatic rendering of current time
+		data = bytearray(2)
+		data[0] = ord('t')
+		data[1] = int(enable)
+		self.safe_write(data)
+
+	def suspend_host(self, restart_timeout_seconds):
+		data = bytearray(3)
+		data[0] = ord('S')
+		data[1] = (restart_timeout_seconds >> 0) & 0xff
+		data[2] = (restart_timeout_seconds >> 8) & 0xff
+		self.safe_write(data)
+
+if __name__ == '__main__':
+	import os
+	import time
+	port = '/dev/tty.usbmodem575711'
+	if not os.path.exists(port):
+		port = '/dev/ttyACM0'
+
+	p = SerialProtocol(port, 115200)
+	p.init_display(256)
+	p.clear_display()
+	p.put_pixel(0, 8, 0, 0)
+	p.put_pixel(8, 0, 8, 0)
+	p.put_pixel(16, 0, 0, 8)
+	p.update_display()
+	time.sleep(1)
+	p.clear_display()