You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
OpenAudio_ArduinoLibrary/examples/BFSK_random/BFSK_random.ino

161 lines
6.1 KiB

/*
* BFSK_random.ino Test the BFSK at 1200 baud with random data
* to determine byte error rate. Vary S/N. A slow process.
* F32 Teensy Audio Librarylibrary
* Bob Larkin 8 June 2022, Rev 15 June 2022
* Public Domain
*/
#include "OpenAudio_ArduinoLibrary.h"
#include "AudioStream_F32.h"
#include <Audio.h>
// Uncomment to see frequency response of input BPF:
// #define PRINT_BPF_FREQ_RESPONSE
int numberSamples = 0;
float* pDat = NULL;
float32_t fa, fb, delf, dAve; // For sweep
struct uartData* pData;
uint32_t errorCount, errorCountFrame;
float32_t inFIRCoef[200];
float32_t inFIRadb[100];
float32_t inFIRData[528];
float32_t inFIRrdb[500];
// A data storage FIFO for send data
float32_t xmitData[128];
int64_t indexIn = 0ULL;
// Correlation data
float32_t xcor[128];
// LPF FIR for 1200 baud
static float32_t LPF_FIR_Sinc[40] = {
0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f,
0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f,
0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f,
0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f,
0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f, 0.025f};
float32_t LPF_FIR_State[128 + 40];
// T3.x supported sample rates: 2000, 8000, 11025, 16000, 22050, 24000, 32000, 44100, 44117, 48000,
// 88200, 88235 (44117*2), 95680, 96000, 176400, 176470, 192000
// T4.x supports any sample rate the codec will handle.
const float sample_rate_Hz = 48000.0f ; // 24000, 44117, or other frequencies listed above (untested)
const int audio_block_samples = 128; // Others untested
AudioSettings_F32 audio_settings(sample_rate_Hz, audio_block_samples); // Not used
RadioBFSKModulator_F32 modulator1(audio_settings);
AudioSynthGaussian_F32 gwn1;
AudioMixer4_F32 mixer4_1;
AudioFilterFIRGeneral_F32 inputFIR;
RadioFMDiscriminator_F32 fmDet1(audio_settings);
UART_F32 uart1(audio_settings);
AudioAnalyzeRMS_F32 rms1;
AudioOutputI2S_F32 audioOutI2S1(audio_settings);
AudioConnection_F32 patchCord1(modulator1, 0, mixer4_1, 0);
AudioConnection_F32 patchCord2(gwn1, 0, mixer4_1, 1);
AudioConnection_F32 patchCord4(mixer4_1, 0, inputFIR, 0);
AudioConnection_F32 patchCord5(inputFIR, 0, rms1, 0);
AudioConnection_F32 patchCord7(inputFIR, 0, fmDet1, 0);
AudioConnection_F32 patchcord8(fmDet1, 0, uart1, 0);
AudioControlSGTL5000 sgtl5000_1;
void setup() {
uint32_t spdb;
static uint16_t dm0;
static uint32_t nn;
Serial.begin(300); // Any value, it is not used
delay(1000);
Serial.println("OpenAudio_ArduinoLibrary - Test BFSK");
Serial.println("Byte error statistics with a random bit pattern.");
delay(1000);
AudioMemory_F32(30, audio_settings);
// Enable the audio shield, select input, and enable output
sgtl5000_1.enable(); //start the audio board
sgtl5000_1.inputSelect(AUDIO_INPUT_LINEIN); // or AUDIO_INPUT_MIC
modulator1.setLPF(NULL, NULL, 0); // No LPF
spdb = modulator1.setBFSK(1200.0f, 10, 1200.0f, 2200.0f);
modulator1.amplitude(1.00f);
Serial.print("Resulting audio samples per data bit = ");
Serial.println(spdb);
gwn1.amplitude(0.5f); // Set S/N
mixer4_1.gain(0, 1.0f); // Modulator in
mixer4_1.gain(1, 1.0f); // Gaussian noise in
// Design a bandpass filter to limit the input to the FM discriminator
for(int jj=0; jj<12; jj++) inFIRadb[jj] = -100.0f;
for(int jj=3; jj<=11; jj++) inFIRadb[jj] = 0.0f;
for(int jj=12; jj<100; jj++) inFIRadb[jj] = -100.0f;
inputFIR.FIRGeneralNew(inFIRadb, 200, inFIRCoef, 40.0f, inFIRData);
#ifdef PRINT_BPF_FREQ_RESPONSE
// Gather the data for a plot of the response. Output goes to Serial Monitor.
// I use highlighting and Ctrl-C to get the data for plotting.
Serial.println("\nResponse of Bandpass Filter ahead of the Discriminator in dB:");
inputFIR.getResponse(500, inFIRrdb);
for(int jj =0; jj<500; jj++)
{
Serial.print(48.0f * (int)jj); Serial.print(","); // Frequency, Hz
Serial.println(inFIRrdb[jj]); // Respnse in dB
}
Serial.println("----------------------------");
#endif
fmDet1.filterOutFIR(LPF_FIR_Sinc, 40, LPF_FIR_State, 0.99f);
fmDet1.initializeFMDiscriminator(1100.0f, 2350.0f, 2.0f, 3.0f);
uart1.setUART(40, 20, 8, PARITY_NONE, 1);
// Next we set the signal and noise
// amplitudes. The pow() equation allows us to enter the S/N directly.
// S/N in dB --v
modulator1.amplitude(pow(10.0, 0.05f*(0.00f-7.65f)));
gwn1.amplitude(1.0f); // Noise fixed, vary signal level
// See BFSKsnr.ino for details
// We can now evaluate the performance of the transmitter and receiver
// by varying the S/N and counting the number of data errors. The data
// will be set randomly over all 8 data bits.
// Thus we can compute error levels vs S/N in dB
for(float32_t snrDB=4.0f; snrDB<=11.0f; snrDB+=0.5f)
//for(float32_t snrDB=11.0f; snrDB<=13.5f; snrDB+=0.5f) // Use with nn=100000
{
modulator1.amplitude(pow(10.0f, 0.05f*(snrDB-7.65f)));
nn = 0;
errorCount = 0;
//while(nn<100000 && errorCount<1000) // Use for S/N > 11 dB
while(nn<10000 && errorCount<1000)
{
if( modulator1.bufferHasSpace() )
{
dm0 = random(255); // Serial.println(dm0);
// Save a copy of sent data in circular buffer
xmitData[indexIn & 0X7F] = (float32_t)dm0;
indexIn++;
modulator1.sendData(0X200 | (dm0 << 1));
nn++;
}
if(uart1.getNDataBuffer() > 0)
{
pData = uart1.readUartData(); // Pointer to data structure
if( pData->data!=xmitData[(indexIn-65LL) & 0X7F] &&
pData->data!=xmitData[(indexIn-66LL) & 0X7F] )
{
errorCount++;
}
}
} // End, waiting for enough data
Serial.print("S/N= "); Serial.print(snrDB, 3);
Serial.print(", number= "); Serial.print(nn);
Serial.print(", errors= "); Serial.println(errorCount);
}
}
void loop() {
}