Posts made by Keybored

@zapta Thanks! I'll change the board design and proceed on this track then. Do you think the lower sensing resolution will impact the quality of the readings?

@zapta Slight change of plans: I found the same sensor, but that works on 3.3V. It's still ±5A, with a lower resolution (230mV/A compared to 350mV/A). It has a lower offset (1.5V) and the full range can be read by the Pico's 3.3V I/O. https://www.mouser.it/ProductDetail/ACEINNA/MCA1101-5-3?qs=PzGy0jfpSMs%252BNw%2FnqBFIdA%3D%3D

It's (theoretically speaking and pinout aside) a direct replacement for the ACS70331. My question now is: firmware-wise, what do I have to adjust? If I understand this correctly, I just have to adapt
//static const SensorSpec GMR_2P5_SENSOR("G2P5A", 2500, 0.4)
to suit my specs
//static const SensorSpec GMR_2P5_SENSOR("G2P5A", 5000, 0.23);.
Should I also uncomment //constexpr int kMaxMilliamps = 2500; and set it to 5000 to read the full scale?
For now, I'm just thinking about the analyzer changes, UI and graphs axis can be adjusted later.
Also, what about the offset? It's the same as the ACS70331, so we should be alright?
Thanks in advance for your time and patience. I really like the project and I want to keep it alive.
Cheers!

@zapta
Thanks for the input! I was thinking about a voltage divider too. That should be extremely easy to compensate for. About the output voltage, I've yet to find how high it goes (shouldn't be more than 4V if we consider the 350mV/A range plus the offset).

The main idea behind this adaptation is to use it above the +/-2.5A range on Nema23 and over. +/-3A would be acceptable but not ideal. I perfectly agree on tackling the 5V issue first. I'm quite sure a divider would work fine with the relatively high frequency of the signal, but insight on that would be much appreciated.

I'm still unsure if the firmware is as easy to adapt as you say. Plus, now that you pointed out, I'll probably keep the 2.5A scale.

Thanks for the help and I'll update you with the schematics

Hi @zapta ,I'm currently adapting the schematic and firmware for a different sensor, the MCA1101-5-5 (available on Mouser). They are +-5A, 350 mV/A, 1.5 MHz and they use the SOIC-16 package, but that's not an issue.
The question I have regards the firmware. I've read the source, and to my understanding, I should change static const SensorSpec GMR_2P5_SENSOR("G2P5A", 5000, 0.35) in hardware_config.cpp, and possibly the initial voltage offset (or is that handled by the Zero calibration?). I should also change the Y-axis values of many of the graphs, but that's easy. Do I have to adjust anything else? (don't bother reading the datasheet if you don't have time, I just need to know if there are other user-defined parameters or constants).
I'll fork the repo once I'm finished
Cheers!