julien-w/pyFirmata

Python interface for the Firmata (http://firmata.org/) protocol. It is compliant with Firmata 2.1. Any help with updating to 2.2 is welcome. Especially the Capability Query and Pin State Query features, as these are quite useful for using it on different boards.

pyFirmata

pyFirmata is a Python interface for the Firmata protocol.

Master tests:

Python 3 tests:

Installation

The preferred way to install is with pip:

pip install pyfirmata

If you install from source with python setup.py install, don't forget to install `pyserial`_ as well.:

git clone https://github.com/tino/pyFirmata
cd pyFirmata
pip install pyserial
python setup.py install

Usage

Basic usage:

>>> from pyfirmata import Arduino, util
>>> board = Arduino('/dev/tty.usbserial-A6008rIF')
>>> board.digital[13].write(1)

To use analog ports, it is probably handy to start an iterator thread. Otherwise the board will keep sending data to your serial, until it overflows:

>>> it = util.Iterator(board)
>>> it.start()
>>> board.analog[0].enable_reporting()
>>> board.analog[0].read()
0.661440304938

If you use a pin more often, it can be worth it to use the get_pin method of the board. It let's you specify what pin you need by a string, composed of 'a' or 'd' (depending on wether you need an analog or digital pin), the pin number, and the mode ('i' for input, 'o' for output, 'p' for pwm). All seperated by :. Eg. a:0:i for analog 0 as input or d:3:p for digital pin 3 as pwm.:

>>> analog_0 = board.get_pin('a:0:i')
>>> analog_0.read()
0.661440304938
>>> pin3 = board.get_pin('d:3:p')
>>> pin3.write(0.6)

Board layout

If you want to use a board with a different layout than the standard Arduino or the Arduino Mega (for which there exist the shortcut classes pyfirmata.Arduino and pyfirmata.ArduinoMega), instantiate the Board class with a dictionary as the layout argument. This is the layout dict for the Mega for example:

>>> mega = {
...         'digital' : tuple(x for x in range(54)),
...         'analog' : tuple(x for x in range(16)),
...         'pwm' : tuple(x for x in range(2,14)),
...         'use_ports' : True,
...         'disabled' : (0, 1, 14, 15) # Rx, Tx, Crystal
...         }

Todo

The next things on my list are to implement the new protocol changes in firmata:

• Capability Query, which would eliminate the need to instantiate a board with the layout dict, as it will be able to determine the layout itself (http://firmata.org/wiki/Proposals#Capability_Query_.28added_in_version_2.2.29)
• Pin State Query, which allows it to populate on-screen controls with an accurate representation of the hardware's configuration (http://firmata.org/wiki/Proposals#Pin_State_Query_.28added_in_version_2.2.29)