IO Zero 32 Python Library

Python Library to use with IO Zero 32 Raspberry Pi development board.

The example python files can be found in /ABElectronics_Python_Libraries/IOZero32/demos

Downloading and Installing the library

To download to your Raspberry Pi type in the terminal:

git clone https://github.com/abelectronicsuk/ABElectronics_Python_Libraries.git

To install the python library navigate into the ABElectronics_Python_Libraries folder and run:

For Python 2.7:

sudo python setup.py install

For Python 3:

sudo python3 setup.py install

If you have PIP installed you can install the library directly from GitHub with the following command:

For Python 2.7:

sudo python2.7 -m pip install git+https://github.com/abelectronicsuk/ABElectronics_Python_Libraries.git

For Python 3:

sudo python3 -m pip install git+https://github.com/abelectronicsuk/ABElectronics_Python_Libraries.git

The IO Zero 32 library is located in the IOZero32 directory

The library requires smbus2 or python-smbus to be installed.

For Python 2:

sudo pip install smbus2

For Python 3:

sudo pip3 install smbus2

Classes:

IOZero32(address, bus)

Parameters:
address: i2c address for the target device. 0x20 to 0x27
bus (optional): I2C bus number (integer). If no value is set the class will try to find the i2c bus automatically using the device name.

Functions:

set_pin_direction(pin, value):

Sets the IO direction for an individual pin
Parameters:
pin: 1 to 16
value: 1 = input, 0 = output
Returns: null

get_pin_direction(pin)

Get the IO direction for an individual pin
Parameters:
pin: pin to read, 1 to 16
Returns: 1 = input, 0 = output

set_port_direction(port, value): 

Sets the IO direction for the specified IO port
Parameters:
port: 0 = pins 1 to 8, 1 = pins 9 to 16
value: number between 0 and 255 or 0x00 and 0xFF. Each bit in the 8-bit number represents a pin on the port. 1 = input, 0 = output
Returns: null

get_port_direction(port): 

Get the direction from an IO port
Parameters:
port: 0 = pins 1 to 8, 1 = pins 9 to 16
Returns: number between 0 and 255 (0xFF)

set_bus_direction(value): 

Sets the IO direction for all pins on the bus
Parameters:
value: 16-bit number 0 to 65535 (0xFFFF). For each bit 1 = input, 0 = output
Returns: null

get_bus_direction()

Get the direction for an IO bus
Returns: 16-bit number 0 to 65535 (0xFFFF). For each bit 1 = input, 0 = output

write_pin(pin, value)

Write to an individual pin 1 - 16
Parameters:
pin: 1 to 16
value: 1 = logic high, 0 = logic low
Returns: null

write_port(port, value)

Write to all pins on the selected port
Parameters:
port: 0 = pins 1 to 8, 1 = pins 9 to 16
value: number between 0 and 255 or 0x00 and 0xFF. Each bit in the 8-bit number represents a pin on the port. 1 = logic high, 0 = logic low
Returns: null

write_bus(value)

Write to all pins on the selected bus
Parameters:
value: 16-bit number 0 to 65535 (0xFFFF). For each bit 1 = logic high, 0 = logic low
Returns: null

read_pin(pin)

Read the value of an individual pin 1 - 16
Parameters:
pin: 1 to 16
Returns: 0 = logic low, 1 = logic high

read_port(port)

Read all pins on the selected port
Parameters:
port: 0 = pins 1 to 8, 1 = pins 9 to 16
Returns: number between 0 and 255 or 0x00 and 0xFF. Each bit in the 8-bit number represents a pin on the port. 0 = logic low, 1 = logic high

read_bus()

Read all pins on the bus
Returns: 16-bit number 0 to 65535 (0xFFFF) Each bit in the 16-bit number represents a pin on the port. 0 = logic low, 1 = logic high

set_pin_polarity(pin, value)

Set the polarity of the selected pin
Parameters:
pin: 1 to 16
value: 0 = same logic state of the input pin, 1 = inverted logic state of the input pin
Returns: null

get_pin_polarity(pin)

Get the polarity of the selected pin
Parameters:
pin: pin to read, 1 to 16
Returns: 0 = same logic state of the input pin, 1 = inverted logic state of the input pin

set_port_polarity(port, value)

Set the polarity of the pins on a selected port
Parameters:
port: 0 = pins 1 to 8, 1 = pins 9 to 16
value: number between 0 and 255 or 0x00 and 0xFF. Each bit in the 8-bit number represents a pin on the port. 0 = same logic state of the input pin, 1 = inverted logic state of the input pin
Returns: null

get_port_polarity(port): 

Get the polarity for the selected IO port
Parameters:
port: 0 = pins 1 to 8, 1 = pins 9 to 16
Returns: number between 0 and 255 (0xFF)

set_bus_polarity(value)

Set the polarity of the pins on the bus
Parameters:
value: 16-bit number 0 to 65535 (0xFFFF). For each bit 0 = same logic state of the input pin, 1 = inverted logic state of the input pin
Returns: null

get_bus_polarity()

Get the polarity of the pins on the bus
Returns: 16-bit number 0 to 65535 (0xFFFF). For each bit 0 = same logic state of the input pin, 1 = inverted logic state of the input pin

Usage

To use the IO Zero 32 library in your code you must first import the library:

from IOZero32 import IOZero32

Next, you must initialise the IOZero32 object with the I2C address of the I/O controller chip. The default addresses for the IO Zero 32 are 0x20 and 0x21:

bus1 = IOZero32(0x20)

We will read the inputs 1 to 8 from bus 1 so set port 0 as inputs.

bus1.set_port_direction(0, 0xFF)

You can now read pin 1 with:

print('Pin 1: ' + str(bus1.read_pin(1)))