Hello
I'd like to output two PWM alternately. Using the timer, PWM1 and PWM2 alternate outputs every 5 seconds. And I want to change duty cycle according to adc value.
void PWM_SWAP(uint32_t period_us)
{
ret_code_t err_code;
//disable PWM for PWM1,2 swap
if(pwm_state == 1)
{
app_pwm_disable(&PWM1); //disable PWM
app_pwm_uninit(&PWM1); //uninitializing PWM
}
else if(pwm_state == 2) //if PWM2 running
{
app_pwm_disable(&PWM2);
app_pwm_uninit(&PWM2);
}
if(pwm_state == 0 || pwm_state == 2) //first time or PWM2 running, PMW1 start
{
app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_1CH(period_us, 27);
// Switch the polarity of the second channel.
pwm1_cfg.pin_polarity[1] = APP_PWM_POLARITY_ACTIVE_HIGH;
// Initialize and enable PWM.
err_code = app_pwm_init(&PWM1,&pwm1_cfg,pwm_ready_callback);
APP_ERROR_CHECK(err_code);
app_pwm_enable(&PWM1);
pwm_state = 1;
}
else if(pwm_state == 1) //PWM1 running, PMW2 swap
{
app_pwm_config_t pwm2_cfg = APP_PWM_DEFAULT_CONFIG_1CH(period_us, 26);
// Switch the polarity of the second channel.
pwm2_cfg.pin_polarity[1] = APP_PWM_POLARITY_ACTIVE_HIGH;
// Initialize and enable PWM.
err_code = app_pwm_init(&PWM2,&pwm2_cfg,pwm_ready_callback);
APP_ERROR_CHECK(err_code);
app_pwm_enable(&PWM2);
pwm_state = 2;
}
}
//timer
static void PWM_swap_timer_handler(void * p_context) //1sec repeate time, toggle PWM1,2 for 5sec
{
swap_timer_count++;
printf("Timer count : %d\n", swap_timer_count);
if(swap_timer_count == 5) //PWM swap every 5sec
{
//PWM_SWAP(adc_freq);
PWM_SWAP(2); //500kHz
swap_timer_count = 0; //count clear
}
}
static void timers_init(void)
{
ret_code_t err_code;
// Initialize timer module.
err_code = app_timer_init();
APP_ERROR_CHECK(err_code);
err_code = app_timer_create(&m_PWM_swap_timer_id,
APP_TIMER_MODE_REPEATED,
PWM_swap_timer_handler);
APP_ERROR_CHECK(err_code);
}
static void PWM_swap_timers_start()
{
ret_code_t err_code;
err_code = app_timer_start(m_PWM_swap_timer_id, APP_TIMER_TICKS(1000), NULL); //1sec repeate
APP_ERROR_CHECK(err_code);
}
//saadc
void timer_handler(nrf_timer_event_t event_type, void * p_context)
{
}
#define ADC_TIME 100 //adc output time
void saadc_sampling_event_init(void) //SAADC example Reference
{
ret_code_t err_code;
err_code = nrf_drv_ppi_init();
APP_ERROR_CHECK(err_code);
//timer setting
nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
timer_cfg.bit_width = NRF_TIMER_BIT_WIDTH_32; //different scan mode example
err_code = nrf_drv_timer_init(&m_timer, &timer_cfg, timer_handler);
APP_ERROR_CHECK(err_code);
/* setup m_timer for compare event every ADC_TIME */
uint32_t ticks = nrf_drv_timer_ms_to_ticks(&m_timer, ADC_TIME);
nrf_drv_timer_extended_compare(&m_timer,
NRF_TIMER_CC_CHANNEL0, //timer channel
ticks, //ADC_TIME
NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, //Shortcut for clearing the timer based on compare 0.
false);
nrf_drv_timer_enable(&m_timer);
uint32_t timer_compare_event_addr = nrf_drv_timer_compare_event_address_get(&m_timer,
NRF_TIMER_CC_CHANNEL0);
uint32_t saadc_sample_task_addr = nrf_drv_saadc_sample_task_get();
/* setup ppi channel so that timer compare event is triggering sample task in SAADC */
err_code = nrf_drv_ppi_channel_alloc(&m_ppi_channel);
APP_ERROR_CHECK(err_code);
err_code = nrf_drv_ppi_channel_assign(m_ppi_channel,
timer_compare_event_addr,
saadc_sample_task_addr);
APP_ERROR_CHECK(err_code);
}
void saadc_sampling_event_enable(void)
{
ret_code_t err_code = nrf_drv_ppi_channel_enable(m_ppi_channel);
APP_ERROR_CHECK(err_code);
}
void saadc_callback(nrf_drv_saadc_evt_t const * p_event)
{
ret_code_t err_code;
if (p_event->type == NRF_DRV_SAADC_EVT_DONE)
{
err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, SAMPLES_IN_BUFFER);
APP_ERROR_CHECK(err_code);
//NRF_LOG_INFO("ADC event number: %d", (int)m_adc_evt_counter);
for (int i = 0; i < SAMPLES_IN_BUFFER; i++)
{
adc1 = p_event->data.done.p_buffer[0];
adc2 = p_event->data.done.p_buffer[1];
//NRF_LOG_INFO("%d", p_event->data.done.p_buffer[i]);
}
m_adc_evt_counter++;
//adc 0~820
if(adc1 < 0)
{
adc1 = 0;
}
else if(adc1 > 820)
{
adc1 = 820;
}
if(adc2 < 0)
{
adc2 = 0;
}
else if(adc2 > 820)
{
adc2 = 820;
}
printf("ADC1 : %d\n", adc1);
printf("ADC2 : %d\n", adc2);
//duty cycle 0~100%
adc_duty1 = (adc1 - 0) * (100 - 0) / (820 - 0) + 0;
adc_duty2 = (adc2 - 0) * (100 - 0) / (820 - 0) + 0;
now_freq = adc_freq; //Check if the frequency value has changed
//printf("ADC_freq : %d\n", adc_freq);
printf("Duty1 : %d\n", adc_duty1);
printf("Duty2 : %d\n", adc_duty2);
}
}
void saadc_init(void)
{
ret_code_t err_code;
//2 channel
nrf_saadc_channel_config_t channel0_config =
NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN1); //p0.003
nrf_saadc_channel_config_t channel1_config =
NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN2); //p0.004
err_code = nrf_drv_saadc_init(NULL, saadc_callback);
APP_ERROR_CHECK(err_code);
err_code = nrf_drv_saadc_channel_init(0, &channel0_config);
APP_ERROR_CHECK(err_code);
err_code = nrf_drv_saadc_channel_init(1, &channel1_config);
APP_ERROR_CHECK(err_code);
err_code = nrf_drv_saadc_buffer_convert(m_buffer_pool[0], SAMPLES_IN_BUFFER);
APP_ERROR_CHECK(err_code);
err_code = nrf_drv_saadc_buffer_convert(m_buffer_pool[1], SAMPLES_IN_BUFFER);
APP_ERROR_CHECK(err_code);
}
static void adc_configure(void)
{
saadc_init();
saadc_sampling_event_init();
saadc_sampling_event_enable();
}
int main(void)
{
timers_init();
adc_configure();
PWM_swap_timers_start();
// Enter main loop.
for (;;)
{
if(pwm_state == 1)
{
APP_ERROR_CHECK(app_pwm_channel_duty_set(&PWM1, 0, adc_duty1));
}
else if(pwm_state == 2)
{
APP_ERROR_CHECK(app_pwm_channel_duty_set(&PWM2, 0, adc_duty2));
}
}
}
When using this code, two PWMs are outputted well for the first few seconds, but after a short period of time, an error occurs in the 'app_pwm_channel_duty_set'
Maybe this is an algorithmic problem, can I get some help with this?
Thank you.
