pyElectronics
This is a python library for using electronics (like i2c or spi devices) with a unified interface. It currently supports connecting to stuff through the Raspberry Pi gpio with the i2c kernel driver and using the Bus Pirate.
Supported gateways
The gateways are the bridge between Linux and the hardware. Currently supported:
- Bus Pirate v3
- Raspberry Pi / other linux i2c_dev supported interfaces
Supported chips/devices
Read the contributing guide to add devices
- Bosch BMP180 Digital pressure sensor
- Honeywell 3-Axis Digital Compass IC HMC5883L
- MPU-6050 Six-Axis (Gyro + Accelerometer) MEMS MotionTracking™ Device
- NXP LM75A Digital temperature sensor
- Microchip MCP23017 16-Bit I/O Expander
Installation
Install it from pypi:
$ pip3 install pyelectronics
The various gateways have their own dependencies. Install the dependencies for the gateway you require:
# Requirements for the Raspberry Pi $ pip3 install pysmbus # Requirements for the Bus Pirate $ pip3 install pyserial
To run the doctests you need all dependencies. You can install them with the doctest requirements file:
$ pip3 install -r docs/doctest-requirements.txt
Usage
Read the full docs at pythonhosted.
First create a instance of a gateway:
from electronics.gateways import BusPirate from electronics.gateways import LinuxDevice # Use a BusPirate to connect to a bus gw = BusPirate('/dev/ttyUSB0') # Use a i2c bus with a linux driver (like the raspberry pi) gw = LinuxDevice(1) # /dev/i2c-1
Create instances for components connected to the gateway:
from electronics.devices import BMP180 from electronics.devices import MPU6050I2C barometer = BMP180(gw, address=0x77) # Address is optional inertia = MPU6050(gw) # Do chip specific initialisation barometer.load_calibration() inertia.wakeup()
Read values from sensors:
temperature = barometer.temperature() pressure = barometer.pressure() acceleration = inertia.acceleration() rotation = inertia.angular_rate()
Example with GPIO:
# Red led conected to the aux pin of the bus pirate red_led = gw.get_aux_pin() # Turn the led on red_led.write(True) # An Microchip port expander connected through I2C expander = MCP23017I2C(gw, address=0x21) # Get the pins for the two other leds that are connected # to the port expander green_led = expander.get_pin('A0') blue_led = expander.get_pin('A1') # Bundle the leds to a bus so you can address 8 colours as an int # the pins on the port expander are open drain, they are inverted with the invert operator (~) bus = GPIOBus([red_led, ~green_led, ~blue_led]) bus.write(0) # Black bus.write(7) # White # Disco! while True: for i in range(0,8): bus.write(i) sleep(0.2)