I make a new question post because I have some other problems with my setup. I use a esp12s 8266 chip. It sends a PWM signal to a n-channel mosfet, so I can regulate the speed of the dc motor that is attached to the drain of the mosfet. The DC motor has extra power from a 9v battery and this battery negative is connected to the GND of the 8266. I can control it with bluetooth hc-05 module, it has 3 options, 40%, 0% (off) and 100% (full power).
Here's the problem: I can control everything and it seems like it works all fine, but when the motor starts spinning I see a yellow led flashing on my 8266 chip and I can't control it anymore. I read about backvoltage from the motor. So I think maybe the backvoltage is causing the chip not to function anymore. To make it work again I need to disconnect and reconnect the chip for it to work again.
So my question is: could this be the backvoltage or something else? And if it's the backvoltage how do I need to connect the diode (1n4001) in this circuit?
I read when a motor stops then the backvoltage happens, but in my case the led on the 8266 starts flashing when it spins. So maybe I hooked something the wrong way. here I have some pictures of the different setups I tried.
Of course I will solder everything nicely, but for now it's just to get a quick impression of the hookup.
Hopefully someone can help me out, thanks in advance!