int main(void)
{
ex_sask_init( );
ADCChannelInit (pADCChannelHandle,adcBuffer);
OCPWMInit (pOCPWMHandle,ocPWMBuffer);
ADCChannelStart (pADCChannelHandle);
OCPWMStart (pOCPWMHandle);
while(1)
{
while(ADCChannelIsBusy(pADCChannelHandle));
ADCChannelRead (pADCChannelHandle,AudioIn,FRAME_SIZE);
ex_audio_process( FRAME_SIZE, AudioIn, AudioWorkSpace, AudioOut );
while(OCPWMIsBusy(pOCPWMHandle));
OCPWMWrite (pOCPWMHandle,AudioOut,FRAME_SIZE);
}
}
int main(void) {
ex_sask_init();
/*Initialise Audio input and output function*/
ADCChannelInit(pADCChannelHandle, adcBuffer);
OCPWMInit(pOCPWMHandle, ocPWMBuffer);
/*Start Audio input and output function*/
ADCChannelStart(pADCChannelHandle);
OCPWMStart(pOCPWMHandle);
/*Initialising variables that are needed for calculating the peak frequency*/
int peakFrequency = 0;
int peakFrequencyBin = 0;
while (1) {
/*Wait till the ADC has a new frame available*/
while (ADCChannelIsBusy(pADCChannelHandle));
/*Read in the Audio Samples from the ADC*/
ADCChannelRead(pADCChannelHandle, frctAudioIn, FRAME_SIZE);
/*Computing the FFT of the raw signal*/
fourierTransform(FRAME_SIZE, compX, frctAudioIn);
/*Removing the negative part of the FFT output (imaginary part) by zeroing it out*/
filterNegativeFreq(FRAME_SIZE, compXfiltered, compX);
/*Compute the square magnitude of the complex FFT output array so we have a Real output vetor*/
SquareMagnitudeCplx(FRAME_SIZE / 2, &compXfiltered[0], &compXfiltered[0].real);
/*Find the frequency Bin ( = index into the SigCmpx[] array) that has the largest energy*/
/*i.e., the largest spectral component*/
VectorMax(FRAME_SIZE / 2, &compXfiltered[0].real, &peakFrequencyBin);
/*Compute the frequency (in Hz) of the largest spectral component*/
peakFrequency = peakFrequencyBin * (8000 / FRAME_SIZE);
/*Uses the peak frequency variable to turn on the corresponding LEDs*/
turnOnLEDs(peakFrequency);
/* Used for checking whether the user wants to record */
if (CheckSwitchS1() == PRESSED) {
if (switchState == 0) {
//startRecording(); Code works, but doesn't record much, only a fraction of a second
} else if (switchState == 1) {
int i = 0;
for (i; i < (FRAME_SIZE)*5; i++) {
frctAudioOut[i] = 0;
}
switchState = 0;
firstPartExecutedDecision = 0;
}
}
/* Switch two is just used to toggle between different modes */
if (CheckSwitchS2() == PRESSED) {
if (switchState2 == 0) {
switchState2 = 1;
} else if (switchState2 == 1) {
switchState2 = 2;
} else if (switchState2 == 2) {
switchState2 = 0;
}
}
/* Checking whether the peak frequency is above 800 and if so calling the function playPureSignal() */
if (peakFrequency >= 800) {
playPureSignal(peakFrequency);
} else if (switchState2 != 2) {
int i = 0;
for (i; i < FRAME_SIZE; i++) {
if (switchState2 == 0) {
frctAudioOut[i] = frctAudioIn[i]; //Used for the mode that allows for outputting of the original signal
} else if (switchState2 == 1) {
frctAudioOut[i] = 0; //Used for the mode that requests silence if the threshold has not been met
}
}
}
if (switchState2 == 2) {
int i = 0;
for (i; i < FRAME_SIZE; i++) {
frctAudioOut[i] = 0;
}
}
/* Outputting the pure signal or original sound or silence, depending on what's inside frctAudioOut*/
while (OCPWMIsBusy(pOCPWMHandle));
OCPWMWrite(pOCPWMHandle, frctAudioOut, FRAME_SIZE);
}
/*=============================================================================
| Function used for recording the input signal, a snapshot of the frame
| is stored inside the frctAudioOut array, this is done five times as that
| was the largest possible size for frctAudioOut array as anything larger would
| lead to exhausting the memory, the function records correctly but the recording
| is not long enough, hence the code was retired as it requires more work.
*===========================================================================*/
void startRecording() {
if (firstPartExecutedDecision == 0) {
int i = 0;
for (i; i < FRAME_SIZE; i++) {
frctAudioOut[i] = frctAudioIn[i]*0.5;
}
firstPartExecutedDecision = 1;
}
if (firstPartExecutedDecision == 1) {
int i = FRAME_SIZE;
int iFrameSize = 0;
for (i; i < (FRAME_SIZE)*2; i++) {
frctAudioOut[i] = frctAudioIn[iFrameSize]*0.5;
iFrameSize++;
}
firstPartExecutedDecision = 2;
}
if (firstPartExecutedDecision == 2) {
int i = (FRAME_SIZE)*2;
int iFrameSize = 0;
for (i; i < (FRAME_SIZE)*3; i++) {
frctAudioOut[i] = frctAudioIn[iFrameSize]*0.5;
iFrameSize++;
}
firstPartExecutedDecision = 3;
}
if (firstPartExecutedDecision == 3) {
int i = (FRAME_SIZE)*3;
int iFrameSize = 0;
for (i; i < (FRAME_SIZE)*4; i++) {
frctAudioOut[i] = frctAudioIn[iFrameSize]*0.5;
iFrameSize++;
}
firstPartExecutedDecision = 4;
}
if (firstPartExecutedDecision == 4) {
int i = (FRAME_SIZE)*4;
int iFrameSize = 0;
for (i; i < (FRAME_SIZE)*5; i++) {
frctAudioOut[i] = frctAudioIn[iFrameSize]*0.5;
iFrameSize++;
}
firstPartExecutedDecision = -1;
switchState = 1;
}
}
/*=============================================================================
| Function used to generate the pure signal using the createSimpleSignal()
| function available in the modulate.h header - this function uses the peak
| frequency handed through the parameter call to decide what signal to generate.
| The output signal is stored inside the frctAudioOut array which is then
| later used for the OCPWMWrite() function to output the sound.
*===========================================================================*/
void playPureSignal(int peakFrequency) {
int simpleSignalFrequency = 0;
if (peakFrequency <= 1600) {
simpleSignalFrequency = 500;
createSimpleSignal(simpleSignalFrequency, FRAME_SIZE, frctAudioOut);
} else if (peakFrequency <= 2400) {
simpleSignalFrequency = 800;
createSimpleSignal(simpleSignalFrequency, FRAME_SIZE, frctAudioOut);
} else if (peakFrequency <= 3200) {
simpleSignalFrequency = 1000;
createSimpleSignal(simpleSignalFrequency, FRAME_SIZE, frctAudioOut);
} else if (peakFrequency <= 4000) {
simpleSignalFrequency = 1500;
createSimpleSignal(simpleSignalFrequency, FRAME_SIZE, frctAudioOut);
}
}
int main(void) //main program
{
ex_sask_init( ); //init sask
ADCChannelInit (pADCChannelHandle,adcBuffer); //init audio input handler
OCPWMInit (pOCPWMHandle,ocPWMBuffer);
ADCChannelStart (pADCChannelHandle); //start audio input handler
OCPWMStart (pOCPWMHandle);
while(1)
{
if(state==0) //Program is in READY state
{
state=0; //set state to 0[READY]
state=displayState(STATE_READY); //call ready state function and read new state back
turnOffAll(); //turn off all LEDs when leaving ready state
}
else if(state==1) //Program is in READ state
{
while(ADCChannelIsBusy(pADCChannelHandle)); //read audio input
ADCChannelRead (pADCChannelHandle,AudioIn,FFT_FRAME_SIZE);
state=3;
}
else if(state==3) //Program is in ANALZYE state
{
int i=0;
analysingState(1);
FFT(&AudioIn, &FFTcompResults); //FFT function used on audio input, using FFT_FRAME_SIZE and returning the results in FFTcompResults
analysingState(2);
generateAuralisation(&AuralisationWorkSpace, &FFTcompResults);
analysingState(3);
for(i=0;i<FFT_FRAME_SIZE;i++)
{
inverseFFT(AudioOut[i], AuralisationWorkSpace[i]);
}
state=displayState(STATE_ANALYSE); //analising finished
}
else if(state==4) //Program is in PLAY BACK state
{
int x;
for(x=0;x<FFT_FRAME_SIZE;x++)
{
while(OCPWMIsBusy(pOCPWMHandle));
OCPWMWrite (pOCPWMHandle,AudioOut[x],FFT_FRAME_SIZE);
playbackState();
}
OCPWMStop (pOCPWMHandle); //stop audio output
state=0;
}
else //Program is in ERROR state
{
state=displayState(STATE_ERROR); //show error state on LEDs and read new state
}
}
}