arduino_serial

It's Mars.

arduino_serial.py is a Python port of Tod E. Kurt's arduino-serial.c program for communicating with an Arduino microcontroller board over a serial port. It only uses standard Python modules (notably termios and fcntl) and does not require any special serial communications modules.

Like Tod's program, you can use it from the command line.

Send the string “a5050” to Arduino:

$ ./arduino_serial.py -b 19200 -p /dev/tty.usbserial-A50018fz -s a5050

This would cause the pan-tilt head described in this previous post to return to its middle position.

Recieve a line of text from Arduino, wait 1000 milliseconds, then send the string “a0000”:

$ ./arduino_serial.py -b 19200 -p /dev/tty.usbserial-A50018fz -r -d 1000 -s a0000

Complete command line usage information:

Usage: arduino-serial.py -p <serialport> [OPTIONS]
Options:
  -h, --help                   Print this help message
  -p, --port=serialport        Serial port Arduino is on
  -b, --baud=baudrate          Baudrate (bps) of Arduino
  -s, --send=data              Send data to Arduino
  -r, --receive                Receive data from Arduino & print it out
  -n  --num=num                Send a number as a single byte
  -d  --delay=millis           Delay for specified milliseconds

Note: Order is important. Set '-b' before doing '-p'.
      Used to make series of actions:  '-d 2000 -s hello -d 100 -r'
      means 'wait 2secs, send 'hello', wait 100msec, get reply'

You can also import arduino_serial and use its SerialPort class to communicate with an Arduino from a Python program.

import arduino_serial

arduino = arduino_serial.SerialPort('/dev/ttyUSB0', 19200)
print arduino.read_until('\n')
arduino.write('a5050')

Posted by jjwiseman at February 06, 2008 07:24 PM