Control brightness with Potentiometer using LED drivers interfacing Raspberry Pi

Thread Starter


Joined Apr 2, 2018
I was checking out this old forums and I found solutions to my qurey but done by PLC equipment and the same thing I wanted to make it work in other way, as I am having Potentiometer which is giving 4-20mA output which drives the LED interfacing with Raspberry Pi using current loop receiver, I need to know what is the best way to use voltage divider to provide desired power supply to Potentiometer as well as raspberry pi ?

Note: I have 12 v DC power supply for whole process

Your suggestions will be appreciated


Joined Feb 20, 2016
Is there any reason you are using a Raspberry Pi and not an Arduino?
The devices you have chosen are pretty expensive. What is your final application? That 4-20mA "Potentiometer" for instance, costs over $30 and the ADC almost $60.
You will also need a 3.3V to 5V interface between the RasPI and the I2C ADC board, and that is another $12. And then there is the RasPi itself.
Do you need 4-20mA or could a pot connected directly to an Arduino work?

Using an Arduino, and a "normal" pot, you will be able to build this all for under $20.
Maybe some more detail of your application may explain your choices, and help with an answer.

Still, with what you have, hook pin 2 of the CM22 to 12V, pin 1 to the CIN1 of the ADC board. GND to the 12V supply 0V.
That should work ok,
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