Use a PIC Microcontroller to Control a Hobby Servo

Step 3 The Circuit

This schematic is actually from something else, but it's ridiculously similar to the one I'll use for a quick demonstration.

The only change that needs to be made for this project is to replace the LED and its resistor with the wire for the control signal. So instead of connecting pin 3 to a resistor and then to an LED and then to ground, just connect pin 3 to the white/yellow wire from the servo. The ICD2 block represents the PIC programmer I used, substitute your own if you want. Also, don't forget to hook up the servo's power and ground connections.

The potentiometer (wiper connected to pin 2) is used here as a voltage divider. A voltage divider is simply two resistors in series with a contact in the middle at which to measure voltage. In this case, the potentiometer is both of the resistors and we adjust their relative proportions by adjusting the potentiometer. It will be used in this project as an analogue input to let us vary the duration of the control signal pulses.

The second image is a bigger version of the schematic. The smaller one just displays better at the size shown on the page.