I have a 4-20mA Receiver click module hooked up to a 5V Arduino. The goal is to have this system be able to measure 4-20mA current.
I'm using a simple resistor - LED circuit for testing, as well as a 4-20mA tester.
- The only time I'm able to measure current is if the circuit is externally powered using a 5V powerbank. I simply hookup the click module in series, and the Arduino can measure the current. However, I notice that without the click module the current is 1.3mA, and with the click module also in the circuit it is about 3.8mA. (or 8mA vs 21mA if I use a different resistor).
- I thought about powering the circuit from the Arduino instead of using an external supply, but the receiver gets really hot, and nothing can be measured. (I'm again putting the click module in series, just like I did with the external battery.
- If I use my 4-20mA tester, externally powered at 12V, the receiver also gets really hot, and nothing can be measured
I'm having trouble understanding why these scenarios aren't working.
I'm also having trouble understanding how the 16V output from the TPS61401 step-up converter in this click module plays a role in these scenarios.
This 16V is responsible for "powering the loop", but in all 3 scenarios, isn't the loop already powered by the provided 5v / 12v ?