Hi,
I've recently got a Current Ranger R3. Currently I have an OLED connected and there is a string "4095 - 6" being printed continuously to the SerialUSB. I've gone through the code on GitHub and as far as I can tell, it shouldn't output anything like that so I was wondering if it is current or if I was reading it wrongly. I'm trying to disable the string so that I can log the readings to USB.
It's something I added in my local firmware for debugging. Specifically the lines below, before the end of the loop inside the if (OLED_found .. ) statement:
SerialUSB.print(adcRead(A1));
SerialUSB.print(" - ");
SerialUSB.println(adcRead(A6));
You can ignore this. When you reflash, use the given calibration values. And make sure you don't have a DUT that is earth referenced (ie. powered from MAINS) if your PCB/USB is also referenced to the same mains earth. Heed the warnings in the guide about this.
Also note that USB will invariably introduce switching noise.
Thanks Felix,
Understood about the USB Switching Noise. I'm just interested in the average current trends. Quick question , what did you mean about the ADC Calibration ? Do you want me to use the calibration values in the sketch or is there someway to have it pick the values in EEPROM.
EEPROM is erased when you reflash firmware.
There was a label with recommended calibration values that were programmed into the CR during initial testing/programming (offset, gain, LDO).