Orangutan and servo control

Can someone sketch out how you would use a Baby Orangutan with the Micro Serial Servo Controller?

I have control of the MSSC down just fine from my PC… but at some point I’ll want to unplug the serial cable and have my bot walk around untethered. I’m confident I can learn to program the Atmel chip, but I’m not at all clear on how I would connect these two boards.

Also, is there a simpler solution for this? Could I connect servos more directly to the Baby Orangutan? If so, how many servos could I reasonably control that way?

Finally, Pololu’s controllers all seem designed for wheeled robots, with onboard (or sold-with) dual motor controllers. The bots I’m getting into now have only servos, not motors. Am I trying to fit a square peg into a round hole here? Does anyone know of an all-in-one programmable servo controller (ideally based on the Atmel chips)?

- Joe


The Baby Orangutan is based on the AVR microcontrollers with hardware UARTs, so unless you want to save that for something else, you would most likely connect the UART TX pin to the servo controller input. Since it’s easy to do serial output without a UART, you could also connect the servo controller to just about any I/O line.

Controlling a few servos yourself is easy, but it can begin taking up a lot of time once you want to control 8 servos. Beyond 8, it gets more difficult since you need to be generating multiple pulses at the same time.

The Orangutans would be a bit of a waste on robots where you have no need for the motor drivers, but I think the Baby Orangutan with a micro servo controller can still be quite competitive for under $50. If you aren’t looking for extra hardware, you could just get an AVR microcontroller (you can get a capable one like the mega644 in a DIP package for under $10, or the mega168 for under $5).

- Jan