Python interface for the Firmata ( protocol. It is compliant with Firmata 2.1. Any help with updating to 2.2 is welcome. The Capability Query is implemented, but the Pin State Query feature not yet.
Latest commit 0cdfcb6 May 17, 2015 @tino Bump version: 1.0.2 → 1.0.3



pyFirmata is a Python interface for the Firmata protocol. It is fully compatible with Firmata 2.1, and has some functionality of version 2.2. It runs on Python 2.7, 3.3 and 3.4.

Test status:


The preferred way to install is with pip:

pip install pyfirmata

You can also install from source with python install. You will need to have setuptools installed:

git clone
cd pyFirmata
python install


Basic usage:

>>> from pyfirmata import Arduino, util
>>> board = Arduino('/dev/tty.usbserial-A6008rIF')

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()

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')
>>> 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
...         }


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