Circuit Lake

Electronic Project and Circuit Collection

Servo Tester for RC Models

04/28/2012 Category: Motor, Project, Renesas, Tools

The application presented here is software driven device that allows the user to test the servo motors used in remote control operated models such as cars, boats, planes and so on. The tester is developed based on M16C/28 microcontroller.

There are many opportunities when one may need to test a servo. Either the servo has been recently bought and the owner wants to check its functionality or the model has been involved in an accident and the owner wants to know what can be salvaged from the model. There are also cases where one wants to run some electrical/mechanical tests and measurements on the servo. In all the situations suggested above, a servo tester may come in handy.

RC Models Servo Tester


In order to test the servo, two parameters, duty cycle and period, of the PWM signal need to be modified to a certain extent by the user. Therefore, the period of the PWM can be changed by appropriately depressing the UP or DOWN buttons. The pulse width can be independently changed by adjusting the potentiometer provided on the development board.

While the test is being performed, the 2 parameters of the rectangular signal are being displayed on the LCD display. The display provides accurate information with regard to the parameters of the PWM control signal. The user can gather information as of how the servo would perform at a certain signal. Parameters such as arm travel and dead band can be evaluated as well.