PI-SPI-DIN-4AO Python Code Samples
4 Channel Analog Output 4-20mA Module
The PI-SPI-DIN-4AO is a 4 channel Analog Output 4-20 mA Module that communicates with the Raspberry Pi via the I2C bus.
The PI-SPI-DIN-4AO has just been upgraded to provide Jumper Selection for:
4-20 mA , 0 to 5VDC and 0 to 10 VDC Outputs.
Here is the Jumper Selection for the various outputs:
This module has a base address of 0x60 which is handled directly by the libwidgetlords library and kernel.
To run the sample Python code examples, please install the Widgetlords libwidgetlords libraries as explained in:
Getting Started with PI-SPI Libraries
NOTE: All of the sample code examples are for Python 3.
Please ensure you have the dtoverlay set correctly in the /boot/config.txt file:
Sample 1 - Write 4 Channels of 4-20 mA Output
In this code example:
1. We import the Widgetlords library
2. Initialize the library
3. Write 4 Analog Output Channels where 800 DA Counts = 4 mA and 4000 DA Counts = 20 mA
from time import sleep
from widgetlords.pi_spi_din import *
outputs = Mod4AO()
Multiple Analog Output Modules - Up to 32 Analog 4-20 mA Outputs
The PI-SPI-DIN-4AO uses a Digital to Analog Converter that has 8 programmable addresses: 0x60 thru 0x67. The libwidgetlords version 2.0 library sample code refers to the addresses as 0 thru 7.
Using the libwidgetlords version 2.0 (or higher) library, each PI-SPI-DIN-4AO module is easy to have it's address re-programmed.
Here is the block diagram of the PI-SPI-DIN-4AO Module: