Frequency and Duty Cycle quesitons

Using Arduino Programming Questions
#1

Hello,

I'm wondering if there's an easy way to set the output of the Arduino's frequency to 50Hz. I understand that the output of the PWM pins is around 500Hz? Am I correct? I'm trying to do this to drive a couple servo motors. I also need to vary the duty cycle. I'm not sure if I should be using digitalWrite() or AnalogWrite().

Right now I'm just using this: 

void setup()
{
  pinMode(10, OUTPUT);
}

void loop()
{
  
  digitalWrite(10, HIGH);
  delay(10); // Approximately 10% duty cycle @ 1KHz
  digitalWrite(10, LOW);
  delay(10);
}

To output my 50Hz square wave. Whenever I try to use pushbuttons to simulate a signal to make the duty cycle change, the duty cycle gets all messed up.

I need to use a 5%, 7.5%, and 10% duty cycle. Any help would be appreciated.

Thank you.

#2

I’m trying to do this to drive a couple servo motors.

Why? There is a perfectly good Servo library.

#3

delay(10); // Approximately 10% duty cycle @ 1KHz

Not even close.

#4

Helghast-Engineer: Any help would be appreciated.

The output timing you've described sound like the standard timing for an ordinary hobby servo. There's a standard library to drive those for you - no need to code this yourself.

#5

If for some reason you do want to program it yourself, you could start by reading the code for the Servo library and the datasheet for the ATmega328 (sections on timers).

#6