Do some of you use these chinese Vm Am modules which are a bit inaccurate for Ampere measurements, but quite ok for voltage, and have experienced total loss?

I'm running these modules connected via a 7805 to a solar panel. So they get 5V Vin, and when the sun shines, they turn on, and if the solar panel voltage is too low, they turn off.

I had 2 of them fail (completely dead, no LEDs, only the voltage regulator still gives 3.3V), and I fear more to come. It seems that these modules die from undervoltage in some conditions where the voltage slowly decreases.

I did not find this out myself, but they say this in a german forum and their explanation seems plausible.

My modules have chips with the STM8 pinout. I suppose that they are chinese copies with flaws.

Does anyone have the same issues with these modules, or other products where chinese microcontroller clones fail similarly?

 

Electronic circuits are not always tolerant to continuous brownouts Chinese or otherwise. One should also consider adding transient suppression to devices connected across solar panels.