NRF52832 SAADC定時器定時轉換
1.在sdk_config.h中加入巨集
// <e> TIMER_ENABLED - nrf_drv_timer - TIMER periperal driver - legacy layer //========================================================== #ifndef TIMER_ENABLED #define TIMER_ENABLED 1 #endif // <o> TIMER_DEFAULT_CONFIG_FREQUENCY - Timer frequency if in Timer mode // <0=> 16 MHz // <1=> 8 MHz // <2=> 4 MHz // <3=> 2 MHz // <4=> 1 MHz // <5=> 500 kHz // <6=> 250 kHz // <7=> 125 kHz // <8=> 62.5 kHz // <9=> 31.25 kHz
#ifndef TIMER_DEFAULT_CONFIG_FREQUENCY #define TIMER_DEFAULT_CONFIG_FREQUENCY 4 #endif
// <o> TIMER_DEFAULT_CONFIG_MODE - Timer mode or operation // <0=> Timer // <1=> Counter
#ifndef TIMER_DEFAULT_CONFIG_MODE #define TIMER_DEFAULT_CONFIG_MODE 0 #endif
// <o> TIMER_DEFAULT_CONFIG_BIT_WIDTH - Timer counter bit width // <0=> 16 bit // <1=> 8 bit // <2=> 24 bit // <3=> 32 bit
#ifndef TIMER_DEFAULT_CONFIG_BIT_WIDTH #define TIMER_DEFAULT_CONFIG_BIT_WIDTH 3 #endif
// <o> TIMER_DEFAULT_CONFIG_IRQ_PRIORITY - Interrupt priority
// <i> Priorities 0,2 (nRF51) and 0,1,4,5 (nRF52) are reserved for SoftDevice // <0=> 0 (highest) // <1=> 1 // <2=> 2 // <3=> 3 // <4=> 4 // <5=> 5 // <6=> 6 // <7=> 7
#ifndef TIMER_DEFAULT_CONFIG_IRQ_PRIORITY #define TIMER_DEFAULT_CONFIG_IRQ_PRIORITY 6 #endif
#ifndef TIMER0_ENABLED #define TIMER0_ENABLED 1 #endif
// <q> TIMER1_ENABLED - Enable TIMER1 instance
#ifndef TIMER1_ENABLED #define TIMER1_ENABLED 1 #endif
// <q> TIMER2_ENABLED - Enable TIMER2 instance
#ifndef TIMER2_ENABLED #define TIMER2_ENABLED 1 #endif
// <q> TIMER3_ENABLED - Enable TIMER3 instance
#ifndef TIMER3_ENABLED #define TIMER3_ENABLED 0 #endif
// <q> TIMER4_ENABLED - Enable TIMER4 instance
#ifndef TIMER4_ENABLED #define TIMER4_ENABLED 0 #endif
// <e> SAADC_ENABLED - nrf_drv_saadc - SAADC peripheral driver - legacy layer //========================================================== #ifndef SAADC_ENABLED #define SAADC_ENABLED 1 #endif // <o> SAADC_CONFIG_RESOLUTION - Resolution // <0=> 8 bit // <1=> 10 bit // <2=> 12 bit // <3=> 14 bit
#ifndef SAADC_CONFIG_RESOLUTION #define SAADC_CONFIG_RESOLUTION 2 #endif
// <o> SAADC_CONFIG_OVERSAMPLE - Sample period // <0=> Disabled // <1=> 2x // <2=> 4x // <3=> 8x // <4=> 16x // <5=> 32x // <6=> 64x // <7=> 128x // <8=> 256x
#ifndef SAADC_CONFIG_OVERSAMPLE #define SAADC_CONFIG_OVERSAMPLE 0 #endif
// <q> SAADC_CONFIG_LP_MODE - Enabling low power mode
#ifndef SAADC_CONFIG_LP_MODE #define SAADC_CONFIG_LP_MODE 0 #endif
// <o> SAADC_CONFIG_IRQ_PRIORITY - Interrupt priority
// <i> Priorities 0,2 (nRF51) and 0,1,4,5 (nRF52) are reserved for SoftDevice // <0=> 0 (highest) // <1=> 1 // <2=> 2 // <3=> 3 // <4=> 4 // <5=> 5 // <6=> 6 // <7=> 7
#ifndef SAADC_CONFIG_IRQ_PRIORITY #define SAADC_CONFIG_IRQ_PRIORITY 6 #endif
2.匯入檔案nrfx_timer.c,nrfx_ssadc.c到工程中
3.引入標頭檔案
#include "nrf_drv_timer.h" #include "nrf_drv_saadc.h"
4.定義變數及巨集
#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.事件處理函式
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.快取池滿處理函式
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.初時化函式
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.在主函式中的處理
/** * @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) { }
}