MMM to power Robostix

The MMM having a switching PSU for the BEC makes it attractive for robotics projects. So long as your brain can take in 5.8v, and not draw too much current, the MMM should do the trick.

A nice little AVR board that is fairly inexpensive and complete is the Robostix by Gumstix (I own the Roboaudiostix.) This board can operate independently of a Gumstix computer or provide a realtime brain for motor control while communicating (and powering) a gumstix computer.

The Robostix and the Roboaudiostix take a voltage between 5.5v and 9v (with voltage above 5.5v being spent in heat.) The MMM outputs clean power at around 5.8v which is darn close to ideal.

The Roboaudiostix, unmodified, will allow the MMM to power other servo's connected to the Roboaudiostix but the board, its self, will require another power source.

On the Roboaudiostix, the PWM (servo) headers negative pins have a connection to ground shared with the BOARD power, and the positive pins are connected to pin one on V_MOTOR. Next V_MOTOR is V0 which is connected to BOARD pin one.

V_MOTOR is there simply to allow for easy installation of an additional power source to keep BOARD power and SERVO power separate. It does not power a motor.

Simply jumpering V0 and V_MOTOR pin one will allow the MMM to power the Roboaudiostix, thus allowing everything to be powered by the MMM.

I cannot speak of the plain Robostix. I have read that the plain Robostix already has V_MOTOR pin one jumpered to BOARD power pin one. If this is true, the plain Robostix requires no modification. Finding out would simply require an ohm meter.

Enjoy.