measuring chopped current with acs714

I there I got a current measurement setup with a acs714 connected to a leonardo. The values of the analog input are reported via the serial using the firmata protocol. In the host software (a selfmade c#) application then i do some smoothing by averaging 30 values or so. This works real fine for constant dc current.

Now I try to mesure a chopped battery current of an brushless esc with brushless motor. Now the values oscillating somehow between a max value and zero. I guess this is because the current draw is not constant but chopped instead. the measuring rate is between 50hz (ir im reading all inputs on arduino ) or about 1Khz if i'm rading just the one analog input. So the reason finally is (I hope it's the right english expression for this...) kind of an overlapping frequency effect.

My idea now to solve this is by smoothing the voltage output of the sensor with a condenser or a RC lowpass filter. But I'm not sure if then the voltage curve is still somehow reporting a usefull average current value?

Any sugestions or remarks?

BR Simon

Yes you can smooth the output with an RC filter. But there is pin 6 on this chip that lets you put a filter before the output. Just increase the value of this.
Be aware that the more you filter it the less responsive will be the current reading. You will get an average value whether that is of use to you depends on your application.

Ok thanks, now I remember seeing this in the datasheet. I'll try with the recommended 1nF but I wil also buy a 10nF and a 100nF in case 1nF is to small. Cheers Simon

And the term for the “overlapping frequency effect” is probably “aliasing”. You need
an anti-aliasing low pass filter in fact.