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SEN0214 20A Analog AC/DC Current Sensor - Problems with readings

userHead richardjsears 2020-05-20 12:10:44 1776 Views4 Replies
Hello -

Among other things I have purchased the SEN0214 20A analog ac/dc current sensor. My goal is to eventually get it running on the Raspberry Pi4 with the DFR0553 ADC, however, I ran into a problem right away getting the ADC to read correctly utilizing this tutorial from DFRobot. When it was all hooked up and running, the program was outputting 2500mV with nothing connected except the actual ac current sensor but nothing connected to it. When I remove the sensor altogether. the readings dropped to 540mV.
Code: Select all
A0:2537mV A1:542mV A2:542mV A3:542mV
A0:2537mV A1:542mV A2:542mV A3:542mV
A0:2540mV A1:542mV A2:542mV A3:542mV

I thought maybe there was an issue with either the code or the ADC so I plugged the current sensor directly into an Arduino and ran this code from DFRobot to test it. Now when I run that code, the output it 0.07 at idle. I thought I was getting close, as the code seemed to indicate that the program would be outputting AC current and 0.07 is pretty near zero.

Next, I took my Fluke 289 True RMS DMM, connected up a 1200 watt heat gun, turned it on low and measured 5.0408 amps of current. Switching the heat gun to high it jumped up immediately to just over 10 amps.

So next I hooked the heat gun up to the current sensor and ran the same test. No luck. On low, it was showing 3.17 (I am assuming amps), off by a large factor.

So before I go back to trying to make it all work through the ADC, I figured I would try and get it working on just an Arduino first and then move to the ADC.

Can anyone shed light on why I would be seeing 5.04 amps on a true RMS DMM vs 3.17 from the current sensor?

Many Thanks!

So i have two problems,
2020-05-28 05:47:04 Thank you. I double checked and I am using the correct (AC) part of the code. It is still off by 2 amps. userHeadPic richardjsears