pyFirmata2 0.9.0

A realtime Python interface for the Firmata procotol

pyFirmata2 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, 3.4, 3.5 and 3.6

Installation

The preferred way to install is with pip:

pip3 install pyfirmata2

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

git clone https://github.com/berndporr/pyFirmata2
cd pyFirmata2
python3 setup.py install

Usage

Basic usage:

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

To switch on contious data acquisition from the inputs of the board run:

>>> board.samplingOn()

and they will be updated approximately every 19ms. To enable sampling with the exact sampling interval (min 10ms):

>>> board.samplingOn(samplinginterval in ms)

The individual analoge pins are enabled / read by:

>>> board.analog[0].enable_reporting()
>>> board.analog[0].read()
0.661440304938

In order to get the data at the given sampling interval register a callback handler:

>>> board.analog[0].register_callback(myCallback)

where myCallback(data) is then called every time when data has been received and is timed by the arduino itself so is very precise of up about 100Hz sampling rate.

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
...         }