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

• 7-segment displays without multiplexing

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)