Digital RC servo tester
circuit diagram of digital rc servo tester with pic12f683
When it's powered on, this servo tester circuit will drive the output with a pulse width of 1.504 ms and a frequency of 50Hz. By pressing of both switches simultaneously, your servo it will turn fast clockwise and anti-clockwise between coresponding servo position for a pulse width of 0.992 ms or 2.016 ms. When the switches are released, the servo it will go to the center position.
I have used a pic12f683 microcontroller specially for the hardware pwm feature. For a fin tuning I have added a RS232 tx interface made with R2,R3, a PC357 optocoupler and an simple diode voltage inverter - C1,C2,D1,D2. Communication is made by a standard RS232 protocol at a baud rate of 9600 bps. It's no problem if you don't use this feature, your servo can work without it. In this case you need just the follow electronic components:
Download source code , schematic and printed circuit board file for Orcad.