void control_init() { //// laser control // Setup Timer0 for a 488.28125Hz "phase correct PWM" wave (assuming a 16Mhz clock) // Timer0 can pwm either PD5 (OC0B) or PD6 (OC0A), we use PD6 // TCCR0A and TCCR0B are the registers to setup Timer0 // see chapter "8-bit Timer/Counter0 with PWM" in Atmga328 specs // OCR0A sets the duty cycle 0-255 corresponding to 0-100% // also see: http://arduino.cc/en/Tutorial/SecretsOfArduinoPWM DDRD |= (1 << DDD6); // set PD6 as an output OCR0A = 0; // set PWM to a 0% duty cycle TCCR0A = _BV(COM0A1) | _BV(WGM00); // phase correct PWM mode // TCCR0A = _BV(COM0A1) | _BV(WGM01) | _BV(WGM00); // fast PWM mode // prescaler: PWMfreq = 16000/(2*256*prescaler) // TCCR0B = _BV(CS00); // 1 => 31.3kHz // TCCR0B = _BV(CS01); // 8 => 3.9kHz TCCR0B = _BV(CS01) | _BV(CS00); // 64 => 489Hz // TCCR0B = _BV(CS02); // 256 => 122Hz // TCCR0B = _BV(CS02) | _BV(CS00); // 1024 => 31Hz // NOTES: // PPI = PWMfreq/(feedrate/25.4/60) //// air and aux assist control ASSIST_DDR |= (1 << AIR_ASSIST_BIT); // set as output pin ASSIST_DDR |= (1 << AUX1_ASSIST_BIT); // set as output pin control_air_assist(false); control_aux1_assist(false); #ifdef DRIVEBOARD ASSIST_DDR |= (1 << AUX2_ASSIST_BIT); // set as output pin control_aux2_assist(false); #else //// limits overwrite control LIMITS_OVERWRITE_DDR |= 1<<LIMITS_OVERWRITE_BIT; // define as output pin control_limits_overwrite(true); // do not use hardware logic to stop steppers #endif }
void control_init() { //// laser control // Setup Timer0 for a 488.28125Hz "phase correct PWM" wave (assuming a 16Mhz clock) // Timer0 can pwm either PD5 (OC0B) or PD6 (OC0A), we use PD6 // TCCR0A and TCCR0B are the registers to setup Timer0 // see chapter "8-bit Timer/Counter0 with PWM" in Atmga328 specs // OCR0A sets the duty cycle 0-255 corresponding to 0-100% // also see: http://arduino.cc/en/Tutorial/SecretsOfArduinoPWM GPIOPinTypeGPIOOutput(LASER_EN_PORT, LASER_EN_MASK); GPIOPinWrite(LASER_EN_PORT, LASER_EN_MASK, LASER_EN_INVERT); // Configure timer SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0); TimerConfigure(LASER_TIMER, TIMER_CFG_SPLIT_PAIR|TIMER_CFG_A_PWM|TIMER_CFG_B_ONE_SHOT); TimerControlLevel(LASER_TIMER, TIMER_A, 1); // PPI = PWMfreq/(feedrate/MM_PER_INCH/60) // Set PPI Pulse timer ppi_cycles = SysCtlClockGet() / 1000 * CONFIG_LASER_PPI_PULSE_MS; ppi_divider = ppi_cycles >> 16; ppi_cycles /= (ppi_divider + 1); TimerPrescaleSet(LASER_TIMER, TIMER_B, ppi_divider); TimerLoadSet(LASER_TIMER, TIMER_B, ppi_cycles); // Setup ISR TimerIntRegister(LASER_TIMER, TIMER_B, laser_isr); TimerIntEnable(LASER_TIMER, TIMER_TIMB_TIMEOUT); IntPrioritySet(INT_TIMER0B, CONFIG_LASER_PRIORITY); // Set PWM refresh rate laser_cycles = SysCtlClockGet() / CONFIG_LASER_PWM_FREQ; /*Hz*/ laser_divider = laser_cycles >> 16; laser_cycles /= (laser_divider + 1); // Setup Laser PWM Timer TimerPrescaleSet(LASER_TIMER, TIMER_A, laser_divider); TimerLoadSet(LASER_TIMER, TIMER_A, laser_cycles); TimerPrescaleMatchSet(LASER_TIMER, TIMER_A, laser_divider); laser_intensity = 0; // Set default value control_laser_intensity(0); control_laser(0, 0); TimerEnable(LASER_TIMER, TIMER_A); // ToDo: Map the timer ccp pin sensibly GPIOPinConfigure(GPIO_PB6_T0CCP0); GPIOPinTypeTimer(LASER_PORT, (1 << LASER_BIT)); //// air and aux assist control GPIOPinTypeGPIOOutput(ASSIST_PORT, ASSIST_MASK); control_air_assist(false); control_aux1_assist(false); }