nrf52832 ADC for ppi

1.在sdk_config.h中加入宏

// SAADC_ENABLED - nrf_drv_saadc - SAADC peripheral driver - legacy layer //========================================================== #ifndef SAADC_ENABLED #define SAADC_ENABLED 1 #endif // SAADC_CONFIG_RESOLUTION  - Resolution   // 8 bit  // 10 bit  // 12 bit  // 14 bit 

#ifndef SAADC_CONFIG_RESOLUTION #define SAADC_CONFIG_RESOLUTION 2 #endif

// SAADC_CONFIG_OVERSAMPLE  - Sample period   // Disabled  // 2x  // 4x  // 8x  // 16x  // 32x  // 64x  // 128x  // 256x 

#ifndef SAADC_CONFIG_OVERSAMPLE #define SAADC_CONFIG_OVERSAMPLE 0 #endif

// SAADC_CONFIG_LP_MODE  - Enabling low power mode  

#ifndef SAADC_CONFIG_LP_MODE #define SAADC_CONFIG_LP_MODE 0 #endif

// SAADC_CONFIG_IRQ_PRIORITY  - Interrupt priority  

// Priorities 0,2 (nRF51) and 0,1,4,5 (nRF52) are reserved for SoftDevice // 0 (highest)  // 1  // 2  // 3  // 4  // 5  // 6  // 7 

#ifndef SAADC_CONFIG_IRQ_PRIORITY #define SAADC_CONFIG_IRQ_PRIORITY 6 #endif

#ifndef PPI_ENABLED #define PPI_ENABLED 1 #endif

// TIMER_ENABLED - nrf_drv_timer - TIMER periperal driver - legacy layer //========================================================== #ifndef TIMER_ENABLED #define TIMER_ENABLED 1 #endif // TIMER_DEFAULT_CONFIG_FREQUENCY  - Timer frequency if in Timer mode   // 16 MHz  // 8 MHz  // 4 MHz  // 2 MHz  // 1 MHz  // 500 kHz  // 250 kHz  // 125 kHz  // 62.5 kHz  // 31.25 kHz 

#ifndef TIMER_DEFAULT_CONFIG_FREQUENCY #define TIMER_DEFAULT_CONFIG_FREQUENCY 4 #endif

// TIMER_DEFAULT_CONFIG_MODE  - Timer mode or operation   // Timer  // Counter 

#ifndef TIMER_DEFAULT_CONFIG_MODE #define TIMER_DEFAULT_CONFIG_MODE 0 #endif

// TIMER_DEFAULT_CONFIG_BIT_WIDTH  - Timer counter bit width   // 16 bit  // 8 bit  // 24 bit  // 32 bit 

#ifndef TIMER_DEFAULT_CONFIG_BIT_WIDTH #define TIMER_DEFAULT_CONFIG_BIT_WIDTH 3 #endif

// TIMER_DEFAULT_CONFIG_IRQ_PRIORITY  - Interrupt priority  

// Priorities 0,2 (nRF51) and 0,1,4,5 (nRF52) are reserved for SoftDevice // 0 (highest)  // 1  // 2  // 3  // 4  // 5  // 6  // 7 

#ifndef TIMER_DEFAULT_CONFIG_IRQ_PRIORITY #define TIMER_DEFAULT_CONFIG_IRQ_PRIORITY 6 #endif

#ifndef TIMER0_ENABLED #define TIMER0_ENABLED 1 #endif

// TIMER1_ENABLED  - Enable TIMER1 instance  

#ifndef TIMER1_ENABLED #define TIMER1_ENABLED 1 #endif

// TIMER2_ENABLED  - Enable TIMER2 instance  

#ifndef TIMER2_ENABLED #define TIMER2_ENABLED 1 #endif

// TIMER3_ENABLED  - Enable TIMER3 instance  

#ifndef TIMER3_ENABLED #define TIMER3_ENABLED 0 #endif

// TIMER4_ENABLED  - Enable TIMER4 instance  

#ifndef TIMER4_ENABLED #define TIMER4_ENABLED 0 #endif 2.导入文件nrfx_ssadc.c,nrfx_ppi.c,nrf_drv_ppi.c,nrfx_timer.c到工程

3.引入头文件

#include "nrf_drv_saadc.h" #include "nrf_drv_ppi.h" #include "nrf_drv_timer.h"

4.定义变量及宏 #define SAMPLES_IN_BUFFER 1 volatile uint8_t state = 1;

static const nrf_drv_timer_t m_timer = NRF_DRV_TIMER_INSTANCE(0); static nrf_saadc_value_t     m_buffer_pool[2][SAMPLES_IN_BUFFER]; static nrf_ppi_channel_t     m_ppi_channel; static uint32_t              m_adc_evt_counter; 5.事件处理函数 void timer_handler(nrf_timer_event_t event_type, void * p_context) {

}

void saadc_callback(nrf_drv_saadc_evt_t const * p_event) {     if (p_event->type == NRF_DRV_SAADC_EVT_DONE)     {         ret_code_t err_code;

        err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, SAMPLES_IN_BUFFER);         APP_ERROR_CHECK(err_code);

        int i;         printf("ADC event number: %d\n", (int)m_adc_evt_counter);

        for (i = 0; i < SAMPLES_IN_BUFFER; i++)         {             printf("%d", p_event->data.done.p_buffer[i]);         }         m_adc_evt_counter++;     } } 6.初时化函数

void saadc_sampling_event_init(void) {     ret_code_t err_code;

    err_code = nrf_drv_ppi_init();     APP_ERROR_CHECK(err_code);

    nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;     timer_cfg.bit_width = NRF_TIMER_BIT_WIDTH_32;     err_code = nrf_drv_timer_init(&m_timer, &timer_cfg, timer_handler);     APP_ERROR_CHECK(err_code);

    /* setup m_timer for compare event every 400ms */     uint32_t ticks = nrf_drv_timer_ms_to_ticks(&m_timer, 5000);     nrf_drv_timer_extended_compare(&m_timer,                                    NRF_TIMER_CC_CHANNEL0,                                    ticks,                                    NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK,                                    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); } 7.在主函数处理     saadc_init();     saadc_sampling_event_init();     saadc_sampling_event_enable();