Hello,
I am trying to change the PWM frequency on some of the pins that are not on a PWM timer.
Looking at the variant.cpp file, (portion shown below)
// 2
{ PIOB, PIO_PB25B_TIOA0, ID_PIOB, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM, TC0_CHA0 }, // TIOA0
{ PIOC, PIO_PC28B_TIOA7, ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM, TC2_CHA7 }, // TIOA7
{ PIOC, PIO_PC26B_TIOB6, ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM, TC2_CHB6 }, // TIOB6
// 5
{ PIOC, PIO_PC25B_TIOA6, ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM, TC2_CHA6 }, // TIOA6
{ PIOC, PIO_PC24B_PWML7, ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_PWM), NO_ADC, NO_ADC, PWM_CH7, NOT_ON_TIMER }, // PWML7
{ PIOC, PIO_PC23B_PWML6, ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_PWM), NO_ADC, NO_ADC, PWM_CH6, NOT_ON_TIMER }, // PWML6
{ PIOC, PIO_PC22B_PWML5, ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_PWM), NO_ADC, NO_ADC, PWM_CH5, NOT_ON_TIMER }, // PWML5
{ PIOC, PIO_PC21B_PWML4, ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_PWM), NO_ADC, NO_ADC, PWM_CH4, NOT_ON_TIMER }, // PWML4
// 10
{ PIOC, PIO_PC29B_TIOB7, ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM, TC2_CHB7 }, // TIOB7
{ PIOD, PIO_PD7B_TIOA8, ID_PIOD, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM, TC2_CHA8 }, // TIOA8
{ PIOD, PIO_PD8B_TIOB8, ID_PIOD, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM, TC2_CHB8 }, // TIOB8
Notice how only channels 6, 7, 8 and 9 have the tag "PWM_CH#". From my understanding and observations, these pins are dynamic and you are able to change the PWM frequencies of these channels, using the follow portion in variant.h
/*
* PWM
*/
#define PWM_INTERFACE PWM
#define PWM_INTERFACE_ID ID_PWM
#define PWM_FREQUENCY 33000
#define PWM_MAX_DUTY_CYCLE 255
#define PWM_MIN_DUTY_CYCLE 0
#define PWM_RESOLUTION 8
Notice that I changed the PWM frequency of the mentioned pins to 33K.
The problem is that this timer only effects channels 6, 7, 8 and 9.
My concern is, how can I change the other pins? I want to be able to change the PWM frequencies of channels 11, 3 and 5. If anyone can help me out with this issue, it is much appreciated.
Thanks,
Daniel