pwm with voltage monitoring

[jetpr]

Hello i need a Idea how run a DC Motor but monitoring the voltage with a A/D pin.

my problem is my Volt Divider is not Stable so mi reading are no correct.

10k and 10.5k in my Divider

[Acetronics2]

Hi, ...

Just read the voltage ... during OFF periods of the PWM drive ...

Alain

[jetpr]

that you mean i have to turn off the motor to read the volts
or
please send a example

thanks

[Acetronics2]

Motor is turned off automatically during PWM off ( or LOW ) periods ...

just sample and hold during this moment.

that's how all ESCs current limiting devices work ... they just sample the power mosfets voltage loss ( = Intensity * Rds ON ... ), and compare with a reference.

Here, the "free running" ( PWM LOW state ... ) voltage of your motor is proportionnal to the rotor speed ...

That's all !!!