You'll find here, more info on: How to control servo with cheap AVR micro-controllers, how to control a Cybot from your PalmOS based device and SmallBASIC. (You can also try with your old HP48).

AVR	ATMEL AVR Opens Source Software: PWM / Servo controllers with GPIO and serial interface.
Palm Cybot	Control a Cybot from your PalmOS based device and SmallBASIC using the servo controller below.

AVR

These modules allow you to control servo motors the same way Pontech.com modules do, but for MUCH less money ! They are based on an Atmel AVR 2313:

servo/servo1.c: Generic PWM and Servo signal generator with RS232 interface.

To use the servo controller you just need to add a few components and a MAX232 for the RS232 interface (use this schematic for example).

You'll find on the CVS Repository:

P.S.: Why Atmel AVR and not Microchip PIC ? 'Cause: It's much faster (10 MIPS @ 10Mhz), cheaper, it has much more registers (32), more features, nicer instruction set, open tools (gcc works nicely)... Go to www.atmel.com for technical evidence. And if you need USB support, use can now use a cheap AVR2313 as a firmware only USB controller thanks to the AVR USB project !