Simple Servo Tester

Circuit diagram

Simple Servo Tester-Circuit diagram
click here to download schematic in pdf

This is a simple servo tester which will comprehensively test the capabilities of almost any modern servo. It has two pushbuttons, CENTRE and SWEEP and a potentiometer which works as follows:

  • CENTRE Does exactly that, centers the servo, afterwards the potentiometer determines position.
  • SWEEP Sweeps the servo back and forth at a rate determined by the potentiometer setting.

The PIC uses its internal timer to set up a constant frame duration of 20ms and the on/off ratio is set by the user.

Have Fun-Ed

PCB board

Simple Servo Tester-PCB board

suggested panel decal

Simple Servo Tester-suggested panel decal


  • R1 = 1K
  • R2 = 10K
  • R3 = 82R
  • R4 = 10K
  • R5 = 5K potentiometer
  • C1 = 27pF
  • C2 = 27pF
  • C3 = 100nF
  • D1 = 4,7V zener diode
  • Q1 = 10MHz crytal
  • IC1 = PIC12F675

Download assembly code (.asm)

Download PCB in Eagle format (.br )

author: EdwardM,
circuit from