Python • Re: Using a 4-20 mA Transmitter with a Raspberry Pi

Unfortunately there is no schema for this transmitter board.
- the only remark in the board description (perhaps you have a schema?) is that it works with 5V supply. Which is unfortunately not a match to RPi which has 3.3V GPIO level. Just to be sure, use an I2C level shifter (*) between RPi and the transmitter board.
- enable the I2C pullup with the jumper switches.
- to measure whether something works, you need to connect an external circuit with a 7.5V to 36V DC supply and a 100 Ohm resistor. 100 Ohm, 20mA is 2V max on the resistor. No remark in the description whether there is a test point for DAC output.

Just for completeness, there is a similar product from microe (**)

For the source code, copy the content of (***) into your test application, perhaps a test.py. The follow the step by step explanation in the readme (****) , chapter "Usage example". What is strange; the default address is denoted with "ADDRESS = 0X67" which should be 0x60.

(*) https://www.adafruit.com/product/757
(**) https://www.mikroe.com/4-20ma-t-click
(***) https://github.com/sergiocaponi/pi_MCP4 ... MCP4725.py
(****) https://github.com/sergiocaponi/pi_MCP4 ... /README.md
(*****) no more links

Statistics: Posted by ghp — Fri Aug 29, 2025 4:33 pm

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