A simple LED board driver example

ledboard.py

#!/usr/bin/env python3

#
# This code is in the public domain.
# Maciej Grela <enki@fsck.pl>
#

import serial

ser = serial.Serial("/dev/ttyUSB0", 115200)

# Some random board with LEDs from a "network appliance".
# It uses a USB connection to send data to a PIC uC
# via an FT245BM converter.
#
# Board layout:
# USB port on the left, looking at leds:
# <USB PORT>
# LED1     LED2 LED3 LED4 LED5 LED6 LED7 LED8 LED9

# A command sent via the serial port with 115200 8N1
# contains 3 bytes:
#
# Cmd := byte1 byte2 byte3
#
# The bits for control bytes are as follows:
#
# byte1
# 00xxxxxx
# |||||||`-- 1: LED1 (green)
# ||||||`--- 1: LED1 (yellow)
# |||||`---- 1: LED2 (green)
# ||||`----- 1: LED2 (yellow)
# |||`------ 1: LED3 (green)
# ||`------- 1: LED3 (yellow)
# |`-------- 0
# `--------- 0
#
# byte2
# 01xxxxxx
# |||||||`-- 1: LED4 (green)
# ||||||`--- 1: LED4 (yellow)
# |||||`---- 1: LED5 (green)
# ||||`----- 1: LED5 (yellow)
# |||`------ 1: LED6 (green)
# ||`------- 1: LED6 (yellow)
# |`-------- 1
# `--------- 0
#
# byte3
# 10xxxxxx
# |||||||`-- 1: LED7 (green)
# ||||||`--- 1: LED7 (yellow)
# |||||`---- 1: LED8 (green)
# ||||`----- 1: LED8 (yellow)
# |||`------ 1: LED9 (green)
# ||`------- 1: LED9 (yellow)
# |`-------- 0
# `--------- 1

# Example command
ser.write([int('00001000', 2), int('01001000', 2), int('10000100', 2)])