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Arduino Diecimila Board Access Inside Linux DEMO. (Python recipe) by Barry Walker
ActiveState Code (http://code.activestate.com/recipes/577631/)

Arduino-Linux2x.py

This is a simple Python example of accessing a(n) Arduino Diecimila Board using Standard Python 2.x.x.

This code requires NO PySerial to work, just standard Linux(/Unix?) commands and a Standard Python install.

The only prerequisite is that a root terminal is needed to start Python in.

This code is released as Public Domain and you can do with it as you please.

To get more values displayed it is best to use a potentiometer wired as one end to +5V, the other end to Gnd and the wiper to ANALOG IN 0. This has been tested on various Linux Distros and kept as simple as possible so that anyone can understand it.

The required ?.pde file for the Arduino Board can be found here:-

http://code.activestate.com/recipes/577625-arduino-diecimila-board-access-inside-winuae-demo/?in=lang-python

Similar assumptions are made as in the URL above.

Enjoy finding simple solutions to often very difficult problems... ;o)

Python, 73 lines
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# Arduino-Linux2x.py
#
# DEMO Arduino test for STANDARD Python 2.5.x or greater under Linux.
# This is an experimental idea only to test the Arduino Diecimila
# development board under at least STANDARD Python 2.5.x and PCLinuxOS 2009.
#
# This working idea is copyright, (C)2009, B.Walker, G0LCU.
# It is NOW issued entirely as Public Domain, you may do with it as you please.
#
# Copy this 'Arduino-Linux2x.py' file into the drawer of your choice
# and you will be ready to roll... ;-)
# Press ~Ctrl C~ to QUIT, OR, set input to maximum of 5V, i.e. 255. 
#
# To run type:-
# >>> execfile("/full/path/to/Arduino-Linux2x.py")<RETURN/ENTER>
# OR alternatively if it is in the module drawer...
# >>> import Arduino-Linux2x<RETURN/ENTER>
#
# IMPORTANT!!! This DEMO requires root access so take the normal precautions.
# (Now tested on Debian 6.0.0 and Python 2.6.6.)

# Do any imports as required.
import os

# Assume root access!!!
# This is not needed in some cases but added for fullness.
os.system("chmod 666 /dev/ttyUSB0")

# Do a basic clear screen...
os.system("clear")

# NOTE:- The next two system calls are separated for ease of understanding.
# It is assumed that the /dev/ttyUSBx device is /dev/ttyUSB0. If yours is
# not just change the 0 for your number, (0 to 7), below.
# ALSO; pySerial, (and others?), is(/are) NOT needed for this AT ALL.
# Fix the speed of the USB-Serial port to 1200 bps...
os.system("stty -F /dev/ttyUSB0 1200")

# Set it to `raw` transfer mode.
os.system("stty -F /dev/ttyUSB0 raw")

# The program proper.
def main():
	print
	print '      Arduino Diecimila Dev Board access demonsration Python 2.5.x code.'
	print '             Original idea copyright, (C)2008, B.Walker, G0LCU.'
	print '                           Press ~Ctrl C~ to QUIT.'
	print

	while 1:
		# Open up a channel for USB/Serial reading on the Arduino board.
		# Place a wire link between ANALOG IN 0 and Gnd.
		# Replace the wire link between ANALOG IN 0 and 3V3.
		# Replace the wire link between ANALOG IN 0 and 5V.
		# Watch the values change.
		pointer = open('/dev/ttyUSB0', 'rb', 2)

		# Transfer an 8 bit number into `mybyte`.
		mybyte = str(pointer.read(1))

		# Immediately close the channel.
		pointer.close()

		# Print the decimal value on screen.
		print 'Decimal value at Arduino ADC Port0 is:-',ord(mybyte),'.    '

		# Ensure one safe getout when running!
		if mybyte == chr(255): break

main()

# End of program...
# Enjoy finding simple sloutions to often very difficult problems...
Tags: access, arduino, demo, linux