Part Number: DK-TM4C129X
Tool/software: Code Composer Studio
Hey,
I am new with this CMSIS DSP library functions. I am currently working on a project that involves computing FFT of external analog signal by function generator. I have successfully sampled the analog signal using ADC triggered by TIMER and used DMA to store the values in an 1024 length array "g_ui8RxBufA". Now, I want to compute the FFT of this signal. I built the CMSIS DSP library successfully and ran the examples given there. I ran the FFT example given in there that calculates FFT of test data signal. I want to proceed like that only. So, the output "g_ui8RxBufA" array, I added 0 value at every odd index of array by using for loop as shown in code (as array indexing starts from 0) to form array " testInput_f32_10khz" (of length 2048) and followed same procedure as in example. But when I ran the code, all the values of " testInput_f32_10khz" array were 0. Somehow, the values are not transferring from "g_ui8RxBufA" array. Can anyone please point out the flaw in the code?
Main function:
uint32_t sysclock;
sysclock = SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
SYSCTL_OSC_MAIN |
SYSCTL_USE_PLL |
SYSCTL_CFG_VCO_480), 120000000);
SysCtlPeripheralEnable(SYSCTL_PERIPH_UDMA);
while(!(SysCtlPeripheralReady(SYSCTL_PERIPH_UDMA)));
SysCtlPeripheralSleepEnable(SYSCTL_PERIPH_UDMA);
IntMasterEnable();
IntEnable(INT_UDMAERR);
uDMAEnable();
uDMAControlBaseSet(pui8ControlTable);
InitUART1Transfer(sysclock);
//FFT begins
uint32_t i;
for(i = 0; i < 1024; i++)
{
//if(i % 2 == 0)
testInput_f32_10khz[2*i] = g_ui8RxBufA[i];
//else
testInput_f32_10khz[2*i + 1] = 0;
}
/* ----------------------------------------------------------------------
* Max magnitude FFT Bin test
* ------------------------------------------------------------------- */
//int32_t main(void)
//{
arm_status status;
float32_t maxValue;
status = ARM_MATH_SUCCESS;
/* Process the data through the CFFT/CIFFT module */
arm_cfft_f32(&arm_cfft_sR_f32_len1024, testInput_f32_10khz, ifftFlag, doBitReverse);
/* Process the data through the Complex Magnitude Module for
calculating the magnitude at each bin */
arm_cmplx_mag_f32(testInput_f32_10khz, testOutput, fftSize);
/* Calculates maxValue and returns corresponding BIN value */
arm_max_f32(testOutput, fftSize, &maxValue, &testIndex);
if (testIndex != refIndex)
{
status = ARM_MATH_TEST_FAILURE;
}
/* ----------------------------------------------------------------------
** Loop here if the signals fail the PASS check.
** This denotes a test failure
** ------------------------------------------------------------------- */
if ( status != ARM_MATH_SUCCESS)
{
while (1);
}
//FFT ends
// while (1); /* main function does not return */
while(1)
{
}
InitUART1Transfer() function:
uint32_t ui32Period;
//uint32_t div;
SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0);
while(!(SysCtlPeripheralReady(SYSCTL_PERIPH_ADC0)));
SysCtlPeripheralSleepEnable(SYSCTL_PERIPH_ADC0);
//ADCClockConfigSet(ADC0_BASE, ADC_CLOCK_SRC_PIOSC | ADC_CLOCK_RATE_FULL, 1);
// ADCClockConfigSet(ADC0_BASE, ADC_CLOCK_SRC_PLL | ADC_CLOCK_RATE_FULL, 30);
ADCClockConfigSet(ADC0_BASE, ADC_CLOCK_SRC_PLL | ADC_CLOCK_RATE_FULL, 24);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
while(!(SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOE)));
GPIOPinTypeADC(GPIO_PORTE_BASE, GPIO_PIN_3);
//ADCSequenceConfigure(ADC0_BASE, 0 /*SS0*/, ADC_TRIGGER_ALWAYS, 3 /*priority*/); // SS0-SS3 priorities must always be different
ADCSequenceConfigure(ADC0_BASE, 0, ADC_TRIGGER_TIMER, 0);
ADCSequenceStepConfigure(ADC0_BASE, 0, 0, ADC_CTL_CH0 | ADC_CTL_IE |
ADC_CTL_END);
ADCSequenceEnable(ADC0_BASE, 0);
ADCIntClear(ADC0_BASE, 0);
// Enable the Timer peripheral
SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);
// Timer should run periodically
TimerConfigure(TIMER0_BASE, TIMER_CFG_PERIODIC);
// Set the value that is loaded into the timer everytime it finishes
// it's the number of clock cycles it takes till the timer triggers the ADC
//#define F_SAMPLE 1000
ui32Period = 120000000/1024000;
TimerLoadSet(TIMER0_BASE, TIMER_A, ui32Period-1);
// Enable triggering
TimerControlTrigger(TIMER0_BASE, TIMER_A, true);
ADCIntEnable(ADC0_BASE, 0);
// Enable the timer
TimerEnable(TIMER0_BASE, TIMER_A);
ADCSequenceDMAEnable(ADC0_BASE, 0);
uDMAChannelAttributeDisable(UDMA_CHANNEL_ADC0,
UDMA_ATTR_ALTSELECT | UDMA_ATTR_USEBURST |
UDMA_ATTR_HIGH_PRIORITY |
UDMA_ATTR_REQMASK);
uDMAChannelControlSet(UDMA_CHANNEL_ADC0 | UDMA_PRI_SELECT,
UDMA_SIZE_32 | UDMA_SRC_INC_NONE | UDMA_DST_INC_32 | UDMA_NEXT_USEBURST |
UDMA_ARB_1024);
uDMAChannelControlSet(UDMA_CHANNEL_ADC0 | UDMA_ALT_SELECT,
UDMA_SIZE_32 | UDMA_SRC_INC_NONE | UDMA_DST_INC_32 | UDMA_NEXT_USEBURST |
UDMA_ARB_1024);
uDMAChannelTransferSet(UDMA_CHANNEL_ADC0 | UDMA_PRI_SELECT,
UDMA_MODE_PINGPONG,
(void *)(ADC0_BASE + ADC_O_SSFIFO0),
g_ui8RxBufA, MEM_BUFFER_SIZE);
uDMAChannelTransferSet(UDMA_CHANNEL_ADC0 | UDMA_ALT_SELECT,
UDMA_MODE_PINGPONG,
(void *)(ADC0_BASE + ADC_O_SSFIFO0),
g_ui8RxBufB, MEM_BUFFER_SIZE);
uDMAChannelEnable(UDMA_CHANNEL_ADC0);
ADCIntEnableEx(ADC0_BASE, ADC_INT_DMA_SS0);
IntEnable(INT_ADC0SS0);
