I’m somewhat new to the whole microcontroller-electronics area and as a first project I decided to work on a line following robot and I’m facing some difficulties on deciding how many regulators will I use and if it’s necessary to use one or two. The parts that I’m definately going to use are the following:
- Arduino UNO with a proto shiled on top with a mini breadboard attached
- QTR-8RC IR sensors using all 8 of them
- An ultrasonic sensor for obstacle detection
- TB6612FNG Dual Motor Driver
- 2 HP Micro Gearmotor 900RPM
- A 7,4 2S LiPo battery
- 9V Step-Up Voltage Regulator U3V70F9
- A 12V DC rocker switch to power on and off the robot
- S7V7F5 5V regulator (not sure about that)
My question is the following. Is it possible-advisable to use only the 9V step up regulator to power the arduino UNO through the Vin pin using the onboard 5V regulator as well as the motor driver? So I will be having two outputs from the same regulator. This particular regulator has built-in reverse voltage protection so I think that there is no danger of back EMF and the motor driver has capacitor filters so there wouldn’t be a noise problem with the system. Or it would be better if solder two wires at the accessories prong of the switch one to power the 9V regulator and the other to power the S7V7F5 5V regulator? Then, I would power the motors from the 9V regulator and the arduino UNO from the 5V regulator through the 5V pin. I know that it’s not advisable to power the arduino UNO through the 5V pin, because it bypasses the onboard regulator but I would be using and external 5V regulator adding reverse voltage protection too using a P type MOSFET transistor so I don’t image that it would be a problem. I’m a bit confused about which approach to take and what are the benefits of the one over the other.
Thanks a lot in advance.