I was setting up a quick project and needed to power a cheap chinese Arduino nano with a 3.7V battery, so I got a cheap boost converter step-up. I adjusted its voltage to around 8V and connected it directly to the Vin Arduino pin.
I was also using an H-Bridge IC (L293D) for controlling a dc motor, which was also being powered by the 8V output.
The circuit worked fine until the motor started, which fried my Arduino. The L293D has protection diodes so I don't think it was related to EMF. (I've used this H-Bridge many times before and never had a problem).
I suspect that whenever there is a current peak on the boost converter, there is a voltage fluctuation (positive and negative) on its output, which is killing the voltage regulator and then the 328P. Since I don't have an oscilloscope, I can not confirm. Have any of you experienced something similar?
I thought maybe adding a large capacitor on the output could solve the problem, but I'm not willing to try since I'm not sure if that's the problem.
I found another topic with a very similar problem: https://forum.arduino.cc/index.php?topic=628916.0
Anyway, sorry if I said anything dumb, I'm still sort of a beginner on the topic.
Thank you and happy 2021!!