I’ve got an Arduino MKR1000 that I’m trying to connect to a 4-AA battery pack, a RFP30N06LE 30A 60V N-Channel Power Mosfet and a push button. My goal is to have the MCU program run once at each push and then turn off the board until the next push, for the sake of low power consumption. The program is a simple and straightforward test: it sets the pin mode to output for the control pin and writes a HIGH. Then it makes the built-in led blink a few times and finally it writes LOW as the control pin output.
I’ve tried most of the solutions I've found online:
- A 10K pulldown resistor between digital output pin and gate to make sure voltage stays low when pin 10 = LOW
- A 100K resistor between gate and source to avoid gate floating
I've read that I should connect the Arduino and the battery pack to a common GND, I'm not sure how to do this while keeping the mosfet into the closed circuit (and therefore creating an open circuit when no voltage is applied to its gate). (==> probably a super-giga n00b question, but hey, I gotta learn the hard way I guess).
One thing I do notice: after running one loop, the "on" built-in led of the Arduino dims down a little. I guess the voltage decreases in the circuit once the output Arduino pin gets a LOW value. But shouldn't the circuit be totally open between drain & source when the gate gets "LOW"?
Also, some measures I've taken:
- between gate and source goes from 3.1V to 2.1V after one program loop (when built-in LED dims down)
- V between drain and source goes from 3.1V to 2.1V after one program loop
- V at pulldown resistor goes from 0.3V to 0.2V after one program loop
- V at gate-source resistor goes from 3.1V to 2.1V after one program loop
I don’t know whether I’m doing the wiring right. I've run a diode test on the mosfet, and it's working fine. I guess my main issue is that the source-drain doesn't close because there's a voltage differential between the gate and the source, hence the gate staying "open".
I hope I've included enough details. Let me know if you need more info. I hope you guys can help me solve that thing!
Have a nice day