DIRECS Developing Intelligent Robots with Enhanced Capabilities

<br> </p> <pre>#include "pwm.h" void setPWMwidth(uint8_t motor, uint8_t value) { // set compare value for the timer channels B and C to "value" // When using standard PWM, this is a 8-bit value! // (max: 0xFF or 255d) switch (motor) { case 1: // drive 1 OCR5B = value; break; case 2: // drive 2 OCR5C = value; break; case 3: // drive 3 [old: cam pan *and* tilt (same, at the moment)] OCR0B = value; break; case 4: // drive 4 [old: cam pan *and* tilt (same, at the moment)] OCR0B = value; break; } } void startPWM(void) { //------------------------------------------------ // drive motors //------------------------------------------------ // turn OFF "power saving mode" for timer 5! // (turn on power for timer) PRR1 &= ~(1<<PRTIM5); // STOP timer 5 //TCCR5B &= ~(1<<CS51); TCCR5B &= ~( (1<<CS50) | (1<<CS51) | (1<<CS52) ); // activate non-inverted phase-correct 8-bit PWM, for counter 5, channel B and C (mode 1) // (Clear OCnB and OCnC on compare match (set output level to zero)) TCCR5A |= (1<<WGM50) | (1<<COM5B1) | (1<<COM5C1); // set timer value to 0 // This is a 16-bit value! However, the compiler handles the 16-bit access! (max: 0xFFF or 65535d) TCNT5 = 0; // START timer 5 and set prescaler to 1024 // Now one cycle of the counter is: 16 MHz / 1024 = 16 kHz -> 0,000064 s -> 64 µs TCCR5B |= (1<<CS50) | (1<<CS52); //------------------------------------------------ // camera motors (pan *and* tilt) //------------------------------------------------ // turn OFF "power saving mode" for timer 0! // (turn on power for timer) // -> not necessary for timer 0. // STOP timer 0 TCCR0B &= ~(1<<CS00); // activate non-inverted phase-correct 8-bit PWM, for counter 0, channel B (mode 1) // (Clear OCnB on compare match (set output level to zero)) TCCR0A |= (1<<WGM00) | (1<<COM0B1); // set timer value to 0 // This is a 8 TCNT0 = 0; // START timer 0 and set prescaler to 1024 // Now one cycle of the counter is: 16 MHz / 1024 = 16 kHz -> 0,000064 s -> 64 µs TCCR0B |= (1<<CS00) | (1<<CS02); } void stopPWM(void) { // STOP timer 5 // TCCR5B &= ~(1<<CS51); TCCR5B &= ~( (1<<CS50) | (1<<CS51) | (1<<CS52) ); // TODO: turn ON "power saving mode" for timer 5! //PRR1 |= (1<<PRTIM5); // STOP timer 0 // TCCR0B &= ~(1<<CS00); TCCR0B &= ~( (1<<CS00) | (1<<CS01) | (1<<CS02) ); // turn ON "power saving mode" for timer 0! // -> not available } </pre> <p><br><br>