On emoncms, is there a way to exclude small values being reported by the CT, which I assume are noise, before the Input gets put into a Feed.
So a function like if less than 5W, ignore input.
I know I can do this within the sketch, but it seems like unnecessary processing.
Re: Exclude Input CT noise values before it is posted to a Feed
Afraid not, although I agree that it's a worthwhile suggestion.
I've coded this within the emonTX sketch, to overcome false readings delivered by my solar inverter during the night, which you have already considered...
Paul
Re: Exclude Input CT noise values before it is posted to a Feed
How do you work out it is night, in your sketch? Or do you just work on threshold?
Have you connected a clock module to your emontx?
Re: Exclude Input CT noise values before it is posted to a Feed
You can get really strange readings from invertors when they go into sleep mode, so I added a line of code to disregard negative readings, also readings less than 20W, so not a perfect solution, but better than seeing -20W in a graph at 2am in the morning.
Re: Exclude Input CT noise values before it is posted to a Feed
OK, I thought you were doing something more creative with a Real Time Clock module attached and excluding the small values only between two time periods.
But I do agree that we need some conditional calibration at the emoncms level rather than suppressing the values at source. emoncms knows the time, so that should be easy too. i.e. only apply correction if time between 2130 - 0530
Re: Exclude Input CT noise values before it is posted to a Feed
I doubt whether using a timer would be effective, because inverters go to sleep and wake up at different times depending upon sunlight according to the time of year, and also factor in weather conditions and DST. In mid winter, I've known my inverter not even bother waking up all day!
I don't think that the 20W threshold makes much difference to accuracy, because I recall when setting this figure, I had noticed that 20W was probably the absolute minimum that it would supply before shutting down anyway.
See this post re power factor.
Paul
Re: Exclude Input CT noise values before it is posted to a Feed
It's extremely strange but the noise level being picked up on my solar CT is less than 1W, but my diversion CT is often picking up between 5-6W even when I know there is no diversion taking place. Ofcourse this is much better because previously with a long CT cable wrapped up next to another power cable it was picking up in excess of 12-15Ws.
So I do think we need some exclusion ability in emoncms so that we can exclude values on different feeds below a certain level. The Calibration function isn't really useful here.