adc

代码下载地址：

https://download.csdn.net/download/qq_31806069/12572633

芯片的P03引脚加入3.3V时读出1020，接入地时读出为0

int main(void)
{

    uint16_t adc;
    char buf[30];
    simple_uart_config(0xff,9,0xff,11,false);
    uart_exit();
    config_adc(AIN4_PIN03);
    
    while(1)
    {

        adc = Adc_Read();
        sprintf(buf,"adc:%d\r\n",adc);
        simple_uart_putstring((const uint8_t *)buf);
        nrf_delay_ms(1000);
    }
}

void config_adc(uint32_t AIN)
{
    uint8_t tab[]={26,27,1,2,3,4,5,6};
    nrf_gpio_cfg_input(tab[AIN],NRF_GPIO_PIN_NOPULL);
    
    NRF_ADC->ENABLE = 0;
    NRF_ADC->CONFIG = (ADC_CONFIG_EXTREFSEL_None << ADC_CONFIG_EXTREFSEL_Pos)
                      /*Bits 17..16 : ADC external reference pin selection. */
                      | ((1<<AIN) << ADC_CONFIG_PSEL_Pos)
                      /*!<Use analog input 2 as analog input. */
                      | (ADC_CONFIG_REFSEL_SupplyOneThirdPrescaling << ADC_CONFIG_REFSEL_Pos)
                      /*!< Use internal 1.2V bandgap voltage as reference for conversion. */
                      | (ADC_CONFIG_INPSEL_AnalogInputOneThirdPrescaling << ADC_CONFIG_INPSEL_Pos)
                      /*!< Analog input specified by PSEL with no prescaling used as inputfor the conversion. */
                      | (ADC_CONFIG_RES_10bit << ADC_CONFIG_RES_Pos);
    /*!< 8bit ADC resolution. */
    NRF_ADC->ENABLE = 1;
    

}

uint16_t Adc_Read(void)
{
    uint16_t adc_data;
    NRF_ADC->TASKS_START = 1;
    while(NRF_ADC->EVENTS_END == 0);
    NRF_ADC->EVENTS_END = 0;
    adc_data = NRF_ADC->RESULT;
    NRF_ADC->TASKS_STOP = 1;

    
    return adc_data;
}