Here is a follow up: @Robert.Wall was so kind to improve the 3-phase firmware this way. With this new firmware the plug&play approach is much more realistic as before. The key improvements are:
- Continuous monitoring of one voltage channel and up to 4 current channels.
- Gives an accurate measure of rapidly varying loads.
- It locks the sample rate of the measurement to the mains frequency. This way the measurement will be done at exactly the same place on the wave (as far as I understood the magic
- The greatest advantage: individually calibration to obtain the correct values for phascal1-3 is not longer necessary! No more complicated calibration procedure and this issue is completely solved.
- One side effect: the emonTx is now also measuring the frequency, which is working quite well. I compared emonTx at different locations and they all show the same frequency and it also fit’s with: Timeline of the utility frequency: Timeline
- many other improvements, like a config menu …
I’m testing this firmware now since some weeks and I’m really happy with it. @glyn.hudson I suggest to replace the old 3-phase firmware with the much improved one, so that everyone can benefit of it.
UPDATE: See pull request for details: Much improved version by Robert Wall by simsasaile · Pull Request #6 · openenergymonitor/emontx-3phase · GitHub