OpenScale suddenly stops reading weight

Sensors Force & Weight
1

Hi,
Am working on a device that measures the dropped weight but I had that problem that openScale suddenly stops reading weight and give me “nan” or random numbers…I had to replace three OpenScales till now

my system consists of 12V power supply, three (100Kg) Loadcells summed by junction box ,Arduino Mega, Three Relays, and openScale… I tried to protect the electronic by flyback diodes but that didn’t help.

The Scenario of damage:

everything would works perfectly till it starts with a sudden freeze in Arduino Serial that even if I reset the arduino manually wont go out So I have to cut the power for like 5 secs and reopen it …at that moment the OpenScale starts to give false values and no hope to reuse it…

what the possibilities for that issue and what can I do to prevent it

2

By OpenScale I presume you mean this one: https://www.sparkfun.com/products/13261. How are you applying +12V to it; Its supply voltage is +5V or USB? Hopefully presuming you are not truly applying +12V to the +5V input, what are the relays for? I am thinking the relays may be for “switching” between the load cells; that would seem a bit troublesome since the sense signals are very sensitive and feed a very sensitive amplifier. So aside from all these potential pitfalls that are possible but not clear from your description; have you had any issues if you pair the OpenScale with only one LoadCell and operated at +5V?