The Cerebellum has eight ports that are commonly used as servo ports, D0 through D7. These ports are also used as digital I/O. Each of these ports can be independently configured in software as servo or digital I/O using the cereb10 header files. It is also possible to use the two PWM ports as servo ports - the PWM ports are specially configured in the PIC's hardware to create pulse width modulated signals up to 80 kHz, significantly higher than the servo signal's 50 Hz frequency. For more information on how servo signals are generated and encode information, see this brief servo signal explanation.

Connecting servos to the Cerebellum

Connecting servos to the Cerebellum is easy, simply place the female header attached to the servo to the Cerebellum male header, with the signal wire connected to the pin nearest to port designator. All servos use either white or yellow wire for signal, red for power, and black for ground.

Choosing a power supply for the servo bus

The servo power bus can be jumper selected to use either the onboard 5V regulated supply, the main input power, or a secondary external power source. Most servos require more current than the 5V supply can source, and operate best at voltages between six and seven volts, so it is best to use either the main input power or an external supply. For more information on how to set the jumpers to configure the servo power bus, see the power bus section of this manual.

Do not use regulated 5V power to power servos or other high current devices, it is possible that you will draw too much current, causing the program running on the Cerebellum to reset.

Always fuse the servo external power supply if you are using it. External power is not protected by the Cerebellum's onboard fuse, nor is it switched off by the main power switch. If you short an unfused external power source and ground together on the Cerebellum, it may permanently damage the Cerebellum and any circuitry attached to it!