Arduino motor shield battery

Projects General Guidance
1

Hi I am using the arduino motor shield with, 2 7.2 volt 380 motors, an arduino uno, a 5V EM-406A GPS, and a 3.3V magnetometer. I did not cut the jumper so the arduino and motor shield are powered with the same battery. I am using a 3000mah 7.2V max 70A battery. My problem is that when everything is running the motors tend to be super weak. Are they "stalling"? Do I need more volts? I also have an 11.1V 1500Mah lipo. Should I try that? Just in case this is a code problem it is attached below. (I am attempting waypoint navigation with an RC tank)

WaypointNavigation.ino (6.07 KB)

2

A 380 motor should be quite lively with 7.2V behind it, assuming the battery actually is putting out 7.2V.

What happens when you connect the motor directly to the battery?

If you're using the Arduino motor shield that is only rated for 2A, which is probably your problem.

3

Should I use a relay?

4

I would check with a multimeter what current you are actually getting to the motor. It wouldn't surprise me if you are only getting 5v and perhaps 40 maH to the motor without cutting the jumper (i.e. the power after the Arduino has regulated it). I suspect if you cut the jumper, and connect the battery to both the Arduino and the port for external power, it might speed up.

5

Ok I cut the jumper and used separate power supplies. Same problem. I'm guessing its either not enough amps or a code issue. I suppose I will try to use a relay next unless anyone has any other suggestions.