Hello, I am trying to make adc sampling on two adc inputs at the same time. The adc example (simulataneous-adc-sampling-from-two-inputs) is not using IRQ handler and applying some delay, but I really want to sample them at the same time. Here is my code and I am checking with nRF-UART app, it seems like the code doesn't work properly. I am very bad at programming. Please help me figure out the problem.
static void adc_init(void)
{
/* Enable interrupt on ADC sample ready event*/
NRF_ADC->INTENSET = ADC_INTENSET_END_Msk;
sd_nvic_SetPriority(ADC_IRQn, NRF_APP_PRIORITY_LOW);
sd_nvic_EnableIRQ(ADC_IRQn);
NRF_ADC->CONFIG = (ADC_CONFIG_EXTREFSEL_None << ADC_CONFIG_EXTREFSEL_Pos) /* Bits 17..16 : ADC external reference pin selection. */
| (ADC_CONFIG_PSEL_AnalogInput2 << ADC_CONFIG_PSEL_Pos) /*!< Use analog input 2 as analog input. */
| (ADC_CONFIG_REFSEL_VBG << 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 input for the conversion. */
| (ADC_CONFIG_RES_8bit << ADC_CONFIG_RES_Pos); /*!< 8bit ADC resolution. */
/* Enable ADC*/
NRF_ADC->ENABLE = ADC_ENABLE_ENABLE_Enabled;
adc_result1 = NRF_ADC->RESULT;
}
static void adc_init2(void)
{
/* Enable interrupt on ADC sample ready event*/
NRF_ADC->INTENSET = ADC_INTENSET_END_Msk;
sd_nvic_SetPriority(ADC_IRQn, NRF_APP_PRIORITY_LOW);
sd_nvic_EnableIRQ(ADC_IRQn);
NRF_ADC->CONFIG = (ADC_CONFIG_EXTREFSEL_None << ADC_CONFIG_EXTREFSEL_Pos) /* Bits 17..16 : ADC external reference pin selection. */
| (ADC_CONFIG_PSEL_AnalogInput6 << ADC_CONFIG_PSEL_Pos) /*!< Use analog input 2 as analog input. */
| (ADC_CONFIG_REFSEL_VBG << 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 input for the conversion. */
| (ADC_CONFIG_RES_8bit << ADC_CONFIG_RES_Pos); /*!< 8bit ADC resolution. */
/* Enable ADC*/
NRF_ADC->ENABLE = ADC_ENABLE_ENABLE_Enabled;
adc_result2 = NRF_ADC->RESULT;
}
/* Interrupt handler for ADC data ready event */
void ADC_IRQHandler(void)
{
uint8_t adc_result1;
uint8_t adc_result2;
/* Clear dataready event */
NRF_ADC->EVENTS_END = 0;
/* Write ADC result both to the UART and over BLE */
// adc_result = NRF_ADC->RESULT;
app_uart_put(adc_result1);
app_uart_put(adc_result2);
ble_nus_send_string(&m_nus, &adc_result1, 1);
ble_nus_send_string(&m_nus, &adc_result2, 1);
nrf_gpio_pin_toggle(LED_3); //indicate on LED that the ADC interrupt handler is executing
//Use the STOP task to save current. Workaround for PAN_028 rev1.5 anomaly 1.
NRF_ADC->TASKS_STOP = 1;
//Release the external crystal
sd_clock_hfclk_release();
}
