Hello,
I want to output in one pin 400kHz and inverse of 400kHz in the other pin. I have somehow managed to output the the 400kHz but haven't managed to output its inverse.
Here is my code:
#include <stdio.h>
#include <string.h>
#include "nrf_drv_pwm.h"
#include "app_util_platform.h"
#include "app_error.h"
#include "boards.h"
#include "bsp.h"
#include "app_timer.h"
#include "nrf_drv_clock.h"
#include "nrf_delay.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#define m_top 20
#define m_step 1
#define led_external 26
#define led_reversed 27
static nrfx_pwm_t m_pwm0 = NRFX_PWM_INSTANCE(0);
uint16_t step = m_top / m_step;
static nrf_pwm_values_common_t sequence_values[m_step * 2];
uint16_t value = 0;
static void pwm_common_init(void)
{
for(int i = 0; i<m_step; i++)
{
value += step;
sequence_values[i] = value;
sequence_values[m_step + i] = m_top - value;
}
nrfx_pwm_config_t const config0 =
{
.output_pins =
{
led_external,
led_reversed| NRFX_PWM_PIN_INVERTED,
NRFX_PWM_PIN_NOT_USED,
NRFX_PWM_PIN_NOT_USED
},
.irq_priority = APP_IRQ_PRIORITY_LOWEST,
.base_clock = NRF_PWM_CLK_16MHz,
.count_mode = NRF_PWM_MODE_UP,
.top_value = m_top,
.load_mode = NRF_PWM_LOAD_COMMON,
.step_mode = NRF_PWM_STEP_AUTO
};
APP_ERROR_CHECK(nrfx_pwm_init(&m_pwm0, &config0, NULL));
}
static void pwm_play(void)
{
nrf_pwm_sequence_t const seq0 =
{
.values = sequence_values,
.length = NRF_PWM_VALUES_LENGTH(sequence_values),
.repeats = 0,
.end_delay = 0
};
(void)nrfx_pwm_simple_playback(&m_pwm0, &seq0, 1, NRFX_PWM_FLAG_LOOP);
}
static void log_init(void)
{
ret_code_t err_code = NRF_LOG_INIT(NULL);
APP_ERROR_CHECK(err_code);
NRF_LOG_DEFAULT_BACKENDS_INIT();
}
int main(void)
{
log_init();
bsp_board_init(BSP_INIT_LEDS);
pwm_common_init();
pwm_play();
NRF_LOG_INFO("PWM application started!!");
}
I was looking into the previous answers but I wasn't able to still apply their solution into my program. From what I know so far is that "NRFX_PWM_PIN_INVERTED" only works in idle state and that "seq_values->channel_0 = duty_cycle | 0x8000" is a possible answer but I am not sure how to integrate that in my program.
Asking for help/advice how to integrate 400kHz output in pin 0.26 and inverse 400kHz frequency in pin 0.27 of nRF52840 board thru modifying my code?
