Hi comrades,

I’m builting a hinged dooropener with arduino nano, two linear drives and two L298N dual H-bridges. I paralleled the two bridges of each L298N to to get the needed current.

As sense resistor I use 3 pcs of 1Ohm/2W SMD-resistors so according to ohm’s law I’ve got a Vrs of 1,1V @ ~3,3 A, so the voltage of the internal voltage reference of the nano.

the problem I’m now facing is, if I make the ADC conversion while the motors are running without load I get a ADC value of <= 0 or >=1023 and this values obviosly exeeding the limits and are therefore unusable …

My guess now is that the motors inductive load are causing noise at the sense resistors and due to the “fast” Nano it detects this overswings?

Does anyone know if I’m right with my guess and what I could do to eliminate this effect? My thought was to use capacitors or an RC network to filter the voltage over the sense-resistors to get a clean and usable voltage?!

I’d appreciate any hint on this!

thx so far!

cheers gueee