I am working on a robot that contains an arduino with a adafruit motor shield. On the robot is a mini servo with a sharpIR sensor. The motor is attached to the bottom which I taken from an old toy. The servo and the sensor both need 5 volts and I do not know how much the motor needs. So my question is how I should power the robot, I do have a couple of 7.2 NI-MH battery's, would this be able to power it?
Here are some photos of the robot:
The Sharp IR sensor needs 5V
The Sharp IR sensor needs 5V and NO MORE than that. You didn’t specify which Arduino board you have, or if it is a clone. The Uno (and others) have a 5V regulator on board. So you can feed it 7-12V DC and the regulator will happily provide 5V to your sensors and servos.
The Adafruit motor shield will run from 4.5 to 36V DC.
Read the info at this link to learn about using the motor shield. They specifically cover using it with an Arduino and how to power it.
