I have created this topic for any comments or support queries about EmonLibCM - Version 2.2.1 (Released 30/10/2021) and subsequent revisions.

I’m not the right person to answer his, however my perception is the mechanism is as follows: Incoming data is dropped into a “slot” depending on its arrival time. While the drift between the sending clock and the receiving clock remains negligible (and of course the ideal starting situation is whe…

I guess in the spirt of “leave no cycle unmeasured” that all argues for the front end accumulating energy locally and sending the current total to emoncms regularly. Then if things fall in the wrong timeslot it just means the consumption was recorded as occurring at the wrong time (slightly), but n…

@Robert.Wall Thank you for providing this code. I’ve been using the non CM version of the library for many years and it has taught me a great deal about my power usage. So I am about to change out some appliances in my home, but before I do that, I wanted to upgrade my library to the CM version s…

[image] rcojoe: Why allow for 5 channels max? Is it to make sure we get enough samples for an accurate average? Basically, yes and because it was written for the Atmel ATMega328P (it does actually say that in the documentation) and that has rather fewer analogue inputs than the Mega2560. Wha…

Actually, the 2560 doesn’t have a second ADC. I sometimes hear it referred to as a “more powerful” Adruino, but for as far as compute power and ADC performance the two are identical. They run the same AVR core at the same clock speeds, and use the same lone ADC. What the 2560 does offer is more p…

@dBC Thanks for clarifying that, I’d taken Joe’s statement at face value. @rcojoe On that basis, I don’t think its feasible to extend the number of channels being monitored beyond 6 (5 current, 1 voltage, giving roughly 32 samples per cycle per channel - 15th harmonic for us but even less for you …

Thank you @dBC and @Robert.Wall . I looked at the ADC for the 2650 last night and I couldn’t find any differences in the ADC so it must be the same ADC. I should only be sampling the pins that need to be sampled by the way I initialized the emonlibcm, keeping my pin count to the 5. 1,2,8,9,10. My…

[image] rcojoe: My readings on 8,9,10 are not as expected OK, when I said the ADCs were identical but for a wider mux I was over-simplifying things a bit. The core of the ADC (and hence its performance) is identical, but sitting in front of it is not only a wider mux but also some op-amps al…

@dBC Yes! That’s the answer to the question I didn’t know to ask!! I did see the same tables in the datasheet and noticed the the MSB was 1 when querying the 8+ pins. It was late and I was trying to figure out where the library was querying the ADC for each pin, which I had not fully comprehende…

You’re welcome. But not exactly. In those tables above they show MUX5:0 as a nice contiguous 6 bits, but the reality is they’re not. MUX4:0 are the bottom 5 bits of ADMUX while MUX5 lives in bit 3 of ADCSRB. Here’s how the Arduino analogRead() handles it… #if defined(ADCSRB) && defined(MUX5) …

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