PIC Servo motor control

Discussion in 'Embedded Systems and Microcontrollers' started by Nadeeja, Jan 24, 2012.

  1. Nadeeja

    Thread Starter New Member

    Jan 24, 2012
    Hi everybody,

    So..I'm new here but I'll get straight down to business.
    I'm using a PIC18f452 to control a servo motor using timers. I could use the PWM module but the point is to actually learn everything I can without taking the easy path.
    So anyway I wrote the firmware in c18, it uses timer0 and timer1. The algorithm is pretty simple.
    The software works well. I attached a LED to the output pin and it dims to the frequency I need.
    However when I connect my servo motor to it, things get weird. It seems my pic constantly restarts with every pulse, but only when I connect the motor.
    To make sure I added a pushbutton that will turn on a LED when pressed.Sure enough the LED turns on when the button is pressed and quickly turns off, meaning the PIC restarts.
    This is driving me crazy...

    Am I missing something? Any help is appreciated.

    P.S - There's nothing wrong with the motor...
  2. Markd77

    Senior Member

    Sep 7, 2009
    Sounds like the current that the servo draws is making the power supply drop. Even a fraction of a second is enough to reset the PIC. More capacitors may help especially close to the PIC.