I'm sorry for my lack of intelligence on the subject, but I'm a bit confused. MarkT I don't quite get this:
Signal ground is _not_ power ground....
So, are the microphone ground and the motor ground connected or not?
The circuit is on a PCB, and I placed a ground plane on the top of the board and a power plane on the bottom of the board. So, everything that says 5V is connected to the bottom, and everything that has a ground symbol is connected to the top of the board.
dc42 I did this:
pcb trace between the positive side of C2 and the Vin pin of MDR as short as possible
But I didn't do this:
the wire from the negative side of C2 and motor negative side/D1 anode needs to be a short as possible
I simply connected both the negative side of C2 and the motor negative side to the top plane. What does making this path short actually do?
Also, can you explain this a little more:
No part of these wires or pcb traces should be in the supply or ground path to any of the sensors or the mcu
Sorry for all the questions! Thank you both!