I have ordered a Dual H-Bridge 12A continuous (30A peak) Polulu motor driver shield for my upcoming (first time ever, a 1.2m long tank made of wood) robot project.
I was thinking about how to supply the power to all the components in the circuit without wasting much power, but the only thing I can come up with is this simple voltage divider connected in parallel to the motor drive:
Knowing the Arduino can handle max 5V I did make sure to make it a bit lower.
But my wonders go to the fact that I am suspicious that connecting the motor driver and Arduino to the same power source isn't a great idea? Or am I paranoid?
And what about power waste by the voltage divider, how can I reduce/minimize it? Make the resistors smaller? (15/10 ohm - but more error and higher current)
Is there a formula to find the most effective R1 and R2?
Do I have to worry about current spikes?
Any other things I could miss in this simple-yet-suspicious circuit?
Also, if I wanted to simulate any possible scenario, which components should I choose in the circuit to keep it as simple as possible (for simulating in Multisim 13)?