We are using the frdmK22F board, so the K22F512. As for the code, we're just using the adc_lptmr_trigger_frdmk22f example located at /KSDK_1.2.0/examples/frdmk22f/demo_apps/adc_hw_trigger/lptmr/kds/ . Some of the most relevant code is attached below, the only changes that we made were to change the ADC_INPUT_CHAN and to explicitly set up pin PTD4 to default mode.
#define ADC_INPUT_CHAN2 (kAdc16Chn8) /* default input signal channel */
#define ADC_INST2 0U
static int32_t init_adc(uint32_t instance)
{
#if FSL_FEATURE_ADC16_HAS_CALIBRATION
adc16_calibration_param_t adcCalibraitionParam;
#endif
adc16_converter_config_t adcUserConfig;
adc16_chn_config_t adcChnConfig;
ADC16_DRV_StructInitUserConfigDefault(&adcUserConfig);
ADC16_DRV_Init(instance, &adcUserConfig);
#if FSL_FEATURE_ADC16_HAS_CALIBRATION
// Auto calibraion.
ADC16_DRV_GetAutoCalibrationParam(instance, &adcCalibraitionParam);
ADC16_DRV_SetCalibrationParam(instance, &adcCalibraitionParam);
#endif
// Initialization ADC for
// 12bit resolution, interrrupt mode, hw trigger enabled.
// normal convert speed, VREFH/L as reference,
// disable continuouse convert mode.
ADC16_DRV_StructInitUserConfigDefault(&adcUserConfig);
adcUserConfig.hwTriggerEnable = true;
adcUserConfig.continuousConvEnable = false;
ADC16_DRV_Init(instance, &adcUserConfig);
// Install Callback function into ISR
ADC_TEST_InstallCallback(instance, 0U, adc_chn0_isr_callback);
ADC_TEST_InstallCallback(instance, 1U, adc_chn1_isr_callback);
adcChnConfig.chnIdx = (adc16_chn_t)ADC_INPUT_CHAN2;
#if FSL_FEATURE_ADC16_HAS_DIFF_MODE
adcChnConfig.diffConvEnable = false;
#endif /* FSL_FEATURE_ADC16_HAS_DIFF_MODE */
adcChnConfig.convCompletedIntEnable = true;
// Configure channel0
ADC16_DRV_ConfigConvChn(instance, 0U, &adcChnConfig);
// Configure channel1, which is used in PDB trigger case
ADC16_DRV_ConfigConvChn(instance, 1U, &adcChnConfig);
return 0;
}
int main(void)
{
uint8_t cnt;
int32_t row;
// init the hardware board
hardware_init();
PORT_HAL_SetMuxMode(PORTD,4u,1);
PRINTF("\r\nadc_hw_trigger demo running...\r\n\r\n");
PORT_HAL_SetMuxMode(PORTD,4u,kPortPinDisabled);
#ifdef USE_DAC_OUT_AS_SOURCE
// use DAC to generate the sine wave
dac_gen_wave();
#else
// If no DAC can be use, then a function generator should
// be used to generate a signal wave, and connect to ADC input
#endif
// initialize the ADC
if (init_adc(ADC_INST2))
{
PRINTF("Failed to do the ADC init\n");
return -1;
}
// setup the HW trigger source
init_trigger_source(ADC_INST2);
// init the print chart array
sparse_reset();
for (cnt = 0; cnt < NR_SAMPLES; cnt++)
{
uint16_t result;
double tmpRatio;
while (gAdcDone != true)
{
;
}
result = ADC16_DRV_GetConvValueRAW(ADC_INST2, (uint32_t)gCurChan);
gAdcDone = false;
// insert the sample data into the sparse matrix
tmpRatio = (double)result / RATIO;
row = (int32_t)tmpRatio;
if (row >= CHART_ROWS)
{
row = CHART_ROWS - 1;
}
// fill one samples into sparse matrix
sparse_insert(row, cnt);
}
// print the chart
for (row = CHART_ROWS - 1; row >= 0; row --)
{
sparse_node_ptr p = gChartHead[row];
uint32_t last = 0;
while (p)
{
for (; last < p->value; last++)
{
PRINTF(" ");
}
PRINTF("*");
p = p->next;
last++;
}
PRINTF("\r\n");
}
// disable the adc0
ADC16_DRV_Deinit(ADC_INST2);
// disable hw trigger source
deinit_trigger_source(ADC_INST2);
#ifdef USE_DAC_OUT_AS_SOURCE
// disable dac source
dac_stop_wave();
#endif
while(1)
{}
}
}
// disable the adc0
ADC16_DRV_Deinit(ADC_INST2);
// disable hw trigger source
deinit_trigger_source(ADC_INST2);
#ifdef USE_DAC_OUT_AS_SOURCE
// disable dac source
dac_stop_wave();
#endif
while(1)
{}
}
