Hi everyone,
I am a proud owner of an emonTx Shield V2, and Arduino Uno and 4 CT sensors(SCT-013-000). I have setup 2 wires to power a 100W light bulb and put 1 CT sensor over one of the wires.
I've loaded Arduino with the SingleCT example code, turn on the light, open the serial and it shows me 0.00 :(
I then moved the sensor in the next jack CT2, now it returns the Irms=0.28 but it does that even if I pull out the CT from the jack or I turn off the light.
Then I tried CT3 it says 0.00 ... CT4 returns 0.28 just like CT2 it doesn't matter if light is on or off :(
Do you think something might be wrong while the soldering?
Do I need to do anything about the jumpers if I don't have RF module? One of the jumpers is set to Uno, the other one is missing :(
Any help is much appreciated.
Thank you
Re: I need some help to get started
What I/O pins are you using in the sketch? Remember the emonTx and the emonTx SHIELD are two different beasts and they use different I/O pins for different functions. So you must use sketches written for the Shield with the Shield, or change the I/O pins around.
The 0.28 A you are reading is noise, getting into the ADC from the digital circuits inside the processor.
Re: I need some help to get started
Thanks for the hints. Problem solved!
Re: I need some help to get started
Hi again,
I have another issue to which i would appreciate your help.
If I run the arduino powered just by the USB I get a fairly accurate reading(40W for a 20W light bulb), but if power the arduino by a 9V 2Amp adaptor, I get a reading of 2000W for the 20W light bulb.
What could be wrong? Adaptor broken, or everything is normal and I just need to calibrate the sensor based on the power source that I have?
Thanks
Re: I need some help to get started
That shouldn't be happening. Am I right in thinking that you are measuring current only?
The first thing to check is the voltage supplied to your Arduino to check that the power supply regulators are working. The processor should be running on 5 V, which you should get on the points marked "5V" on the shield. I don't know the details of Arduino boards so I can't help much.
Secondly, even if the supply isn't exactly 5 V, you still shouldn't read 100 × the correct current, so something is badly wrong. The power is calculated assuming a voltage of 230 V, if yours is different then the power will be wrong, but again not 100 ×.
Re: I need some help to get started
Yeah, measuring current only. I'll check the shield 5V pin if its indeed 5V. Thanks