SparkFun Forums

[radioactivqted]

Hello,

I am working on a robotic system that uses four different stepper motors. Because of the different current ratings of the motors, I have one running on a L293N driver board, one on an EasyDriver, one on a Big EasyDriver, and the last one on an Autodriver v10. When I run my code using only the three non-AutoDriver steppers, each one works as expected. However, when I include the line that runs the AutoDriver, all of the motors stop, only jittering occasionally.

I have the AutoDriver configured in setup(), so could this be an issue with the SPI connection or chip select? (I'm using an Arduino Mega 2560.) What might be causing all the other motors to stop running?

[jremington]

Your motor power supply is almost certainly inadequate. Post the current requirements for each the motors, and describe the power source voltage and current capability.

[radioactivqted]

The entire system is running on two VEX 3000mAh NiMH batteries at 7.2V each. The AutoDriver has a dedicated battery for motor power; all other motors are connected to the other battery.
The motor that's connected to the AutoDriver is rated for 2.8A.
You know, now that I consider it, 7.2V is pretty low for such a large motor. But I'm not sure why it would cause all the other steppers to stop.

[jremington]

From Sparkfun's description of Autodriver:

STMicro’s L6470 is a 3A, 8-45V bipolar stepper motor driver.

Note the "8".