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)