I need a lot of AD data at 1MHz speed.
I am testing with adcBufTemperature example.
I only changed samplingFrequency and samplesRequestedCount in this example, and added ADCBuf_convert() in the while loop.
/* Set up an ADCBuf peripheral in ADCBuf_RECURRENCE_MODE_CONTINUOUS */
ADCBuf_Params_init(&adcBufParams);
adcBufParams.callbackFxn = adcBufCallback;
adcBufParams.recurrenceMode = ADCBuf_RECURRENCE_MODE_ONE_SHOT;
adcBufParams.returnMode = ADCBuf_RETURN_MODE_CALLBACK;
adcBufParams.samplingFrequency = 1000000;
adcBuf = ADCBuf_open(CONFIG_ADCBUF_0, &adcBufParams);
if (!adcBuf){
/* AdcBuf did not open correctly. */
while(1);
}
/* Configure the conversion struct */
continuousConversion.arg = NULL;
continuousConversion.adcChannel = CONFIG_ADCBUF_0_CHANNEL_0;
continuousConversion.sampleBuffer = sampleBufferOne;
continuousConversion.sampleBufferTwo = sampleBufferOne;
continuousConversion.samplesRequestedCount = 1000;
/*
* Go to sleep in the foreground thread forever. The data will be collected
* and transfered in the background thread
*/
while(1) {
if (ADCBuf_convert(adcBuf, &continuousConversion, 1) !=
ADCBuf_STATUS_SUCCESS) {
/* Did not start conversion process correctly. */
while(1);
}
/* Wait for semaphore and print average temperature */
sem_wait(&adcbufSem);
/* Print a message with average temperature */
Display_printf(displayHandle, 0, 0, "The average temperature is %.3fC",
avgTemperature);
}
However, after a few loops, adcBufCallback() no longer occurs.
Are there any limits on the sampling rate?
Also, the overflow flag is raised in ADC_OSTAT. Can I ignore it?
