NRF52832 SAADC定时器定时转换

1.在sdk_config.h中加入宏

// 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

// 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

2.导入文件nrfx_timer.c,nrfx_ssadc.c到工程中

3.引入头文件

#include "nrf_drv_timer.h" #include "nrf_drv_saadc.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) {     ret_code_t err_code;     switch(event_type)     {         case NRF_TIMER_EVENT_COMPARE0:             err_code = nrfx_saadc_sample();             APP_ERROR_CHECK(err_code);             break;         default:             break;     } }

6.缓存池满处理函数

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("\nADC 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++;     } }

7.初时化函数

void saadc_init(void) {     ret_code_t err_code;     nrf_saadc_channel_config_t channel_config =         NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN7);

    err_code = nrf_drv_saadc_init(NULL, saadc_callback);     APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_saadc_channel_init(0, &channel_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);

}

void saadc_sampling_event_init(void) {     ret_code_t 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, 1000);     nrf_drv_timer_extended_compare(&m_timer,                                    NRF_TIMER_CC_CHANNEL0,                                    ticks,                                    NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK,                                    true);     nrf_drv_timer_enable(&m_timer);

}

8.在主函数中的处理

/**  * @brief Function for main application entry.  */ int main(void) {     uint32_t err_code;

    bsp_board_init(BSP_INIT_LEDS);

    const app_uart_comm_params_t comm_params =       {           RX_PIN_NUMBER,           TX_PIN_NUMBER,           RTS_PIN_NUMBER,           CTS_PIN_NUMBER,           UART_HWFC,           false, #if defined (UART_PRESENT)           NRF_UART_BAUDRATE_115200 #else           NRF_UARTE_BAUDRATE_115200 #endif       };

    APP_UART_FIFO_INIT(&comm_params,                          UART_RX_BUF_SIZE,                          UART_TX_BUF_SIZE,                          uart_error_handle,                          APP_IRQ_PRIORITY_LOWEST,                          err_code);

    APP_ERROR_CHECK(err_code);

    saadc_init();     saadc_sampling_event_init();        while (true)     {                     }

}