Sending speed command to M1 kills my Baby Orangutan

I’m having trouble programming my baby orangutan and I think that something may be broken inside the board.

I’m using the Baby Orangutan to control 2 DC motors. I control the motor speed with my phone via bluetooth: Phone --BT–> arduino --I2C–> Baby O.
After lots of debugging and reducing the code to just “setSpeeds” I got to the point where I can control the speed of M2 but if I set M1’s speed to anything other than 0 both motors stop working (I just get a buzzing sound). What could cause such a weird behavior???

Here’s the code:

#include <OrangutanMotors.h>

void setup() 
}  // end of setup

void loop() 
}  // end of loop

That may be a power problem. What motors are you using (voltage rating, stall current and running current) and how are you powering the Baby O?

Try swapping the motors between M1 and M2, to isolate the problem.

Generally I use LiPo batteries but for debugging purposes I’m using a power supply. When I set only M2 speed everything works fine, the unit supplies the 1.6A stall torque without trouble. I didn’t check current draw when M1 is also active… Could a shorted motor be causing the problem?

I was hoping to avoid resoldering any wires but it seems inevitable.


It sounds like the H-bridge on the Baby Orangutan might be damaged. How were you powering it when it stopped working properly? Can you post pictures showing how you had it connected at that time?

- Amanda

I don’t remember exactly and I don’t have the robot with me right now but the general idea is:
The BO is connected to 2 motors (on M1A, M1B, M2A, M2B) and 2 encoders (I think PB0, PB1, PB2, PB5. I recall there was a problem with PB4 and the ISP lines so I moved one of the cables). The BO is connected to the power supply (batteries) on VIN+GND and supplies power to the encoders via VCC+GND. I’ll post a pic when I go back to the lab.

Is it possible that the motor drew too much current for too long and ended up burning the H-bridge?
If I recall correctly the BO is rated for 1A and the motor takes 1.6A when stalled.

The Baby Orangutan can only deliver 1A continuously but can handle 3A peak per channel. The driver has a thermal shutdown, so it is not likely that you damaged it from drawing too much current over an extended period of time; however, large bursts of current (maybe from quickly switching directions at full speed) could potentially damage it.

Can you tell us what you used as a power source and send us pictures of your setup as I asked in my previous post?

- Amanda