that would have been entertaining and a shock to the mosquito
Id definately try a seperate power supply for arduino but still join negative terminal to negative on the rest of the circuit to maintain a common ground .
Im sure you will nut it all out .
They say if you go over 12 volts into an L298n motor driver, to pull the jumper out and not use the 5v regulated output to power any controllers.. So yeah, that's probably the main problem..
I'll have to start a new thread soon. All about cannabis and mad ultrasound experiments..