AlignLR added normalization to remove threshold.

pull/13/head
boblark 3 years ago
parent 8702b04e7b
commit ec3d395a45
  1. 19
      AudioAlignLR_F32.cpp
  2. 30
      AudioAlignLR_F32.h
  3. 139
      examples/TestTwinPeaks/TestTwinPeaks.ino

@ -89,21 +89,30 @@ void AudioAlignLR_F32::update(void) {
{
currentTPinfo.xcVal[j] += block_i->data[k] * block_q->data[k+j];
}
currentTPinfo.xNorm = 0.0f;
for(k=0; k<4; k++)
currentTPinfo.xNorm += fabsf( currentTPinfo.xcVal[k] );
}
// Decision time. Still in Measure. Can we leave? Need one more update()?
// Sort out the offset that is cross-correlated
if(currentTPinfo.nMeas>5) // Get past junk at startup
if(currentTPinfo.nMeas>5 && currentTPinfo.xNorm > 0.0001f) // Get past junk at startup
{
currentTPinfo.TPerror = ERROR_TP_NONE; // Change later if not true
needOneMore = true; // Change later if not true
if(currentTPinfo.xcVal[0]>TPthreshold && currentTPinfo.xcVal[2]<-TPthreshold)
// Redo (12 March 2022) with normalized values
float32_t xcN[4];
for(j=0; j<4; j++)
xcN[j] = currentTPinfo.xcVal[j]/currentTPinfo.xNorm;
// Look for a good cross-correlation with the normalized values
if(xcN[0] - xcN[2] > 0.75f)
currentTPinfo.neededShift = 0;
else if(currentTPinfo.xcVal[1]>TPthreshold && currentTPinfo.xcVal[3]<-TPthreshold)
else if(xcN[1] - xcN[3] > 0.75f)
currentTPinfo.neededShift = 1;
else if(currentTPinfo.xcVal[3]>TPthreshold && currentTPinfo.xcVal[1]<-TPthreshold)
else if(xcN[3] - xcN[1] > 0.75f)
currentTPinfo.neededShift = -1;
else // Don't have a combination above the threshold.
else // Don't have a combination awith much cross-correlation
{
currentTPinfo.neededShift = 0; // Just a guess
currentTPinfo.TPerror = ERROR_TP_BAD_DATA; // Probably no, or low signal

@ -54,6 +54,30 @@
//
// BETA NOTE That calls and operations may change. BETA
// Rev 12 Mar 2022 Added normalized decisions to eliminate need for a threshold.
/* This is best placed in the setup() part of the INO. A signal needs to be generated
* and this would look like:
uint32_t timeSquareWave = 0;
#define PIN_FOR_TP 2
pinMode (PIN_FOR_TP, OUTPUT); // Digital output pin
pData = TwinPeak.read(); // Base data to check error
while (pData->TPerror < 0 && millis()-tMillis < 2000) // with timeout
{
if(micros()-timeSquareWave >= 45 && pData->TPstate==TP_MEASURE)
{
timeSquareWave = micros();
squareWave = squareWave^1;
digitalWrite(PIN_FOR_TP, squareWave);
}
pData = TwinPeak.read();
}
digitalWrite(PIN_FOR_TP, 0); // Set pin to zero
* where the 45 microseconds needs to be adjusted for the sample rate of the Codec
*/
#ifndef audio_align_lr_f32_h_
#define audio_align_lr_f32_h_
@ -76,6 +100,7 @@ struct TPinfo{
uint16_t TPstate;
uint32_t nMeas;
float32_t xcVal[4]; // I-Q cross-correlation sums
float32_t xNorm;
int16_t neededShift;
int16_t TPerror;
uint16_t TPsignalHardware;
@ -139,7 +164,8 @@ public:
}
void setThreshold(float32_t _TPthreshold) {
TPthreshold = _TPthreshold;
//TPthreshold = _TPthreshold;
Serial.println("ERROR: Threshold is no longer used. 12 Mar 2022");
}
virtual void update(void);
@ -151,7 +177,7 @@ private:
bool controlPinInvert = true;
uint16_t block_size = 128;
bool needOneMore = false;
float32_t TPthreshold = 1.0f;
// float32_t TPthreshold = 1.0f;
float32_t TPextraI = 0.0f;
float32_t TPextraQ = 0.0f;
TPinfo currentTPinfo;

@ -1,4 +1,4 @@
/* TestTwinPeaks.ino Bob Larkin 26 Feb 2022
/* TestTwinPeaks.ino Bob Larkin 26 Feb 2022 1
* Tests the AlignLR class for finding the relative
* time order of the Codec ADC L and R channels, and then
* corrects these offsets.
@ -15,6 +15,9 @@
*
*/
// Beta rev 12 Mar 2022: Added normalized measures and removed threshold. Moved
// the L-R alignment to setup().
#include "Audio.h"
#include "OpenAudio_ArduinoLibrary.h"
@ -29,10 +32,7 @@
//
// Set threshold as needed. Examine 3 output data around update #15
// and use about half of maximum positive value.
#define TP_THRESHOLD 11.0f
//
// Un-comment the next to print samples of the phase-adjusted L&R data
// #define PRINT_OUTPUT_DATA
// #define TP_THRESHOLD 0.001f <<<< No Longer Used
//
// End Control Panel
@ -40,10 +40,14 @@ const float sample_rate_Hz = 44100.0f;
const int audio_block_samples = 128;
AudioSettings_F32 audio_settings(sample_rate_Hz, audio_block_samples);
uint16_t nMeasLast = 0;
uint32_t timeSquareWave = 0; // Switch every 45 microseconds
TPinfo* pData;
uint32_t timeSquareWave = 0; // Switch every twoPeriods microseconds
uint32_t twoPeriods;
AudioInputI2S_F32 i2sIn;
// BEWARE _ -- The SIGNAL_HARDWARE==TP_SIGNAL_CODEC is likely to be removed and
// then the constructtion of the object will be *ONLY* the simple cases
// of TwinPeak(audio_settings) or just TwinPeak
// Pin or Codec Pin, Invert
AudioAlignLR_F32 TwinPeak(SIGNAL_HARDWARE, PIN_FOR_TP, false, audio_settings);
AudioOutputI2S_F32 i2sOut;
@ -57,18 +61,27 @@ AudioConnection_F32 connection1(i2sIn, 0, TwinPeak, 0);
AudioConnection_F32 connection2(i2sIn, 1, TwinPeak, 1);
#if SIGNAL_HARDWARE==TP_SIGNAL_CODEC
AudioConnection_F32 connection4(TwinPeak, 2, i2sOut, 0); // DAC L
AudioConnection_F32 connection6(TwinPeak, 2, i2sOut, 1); // DAC R
// Not realistic for a radio but useful for testing
AudioConnection_F32 connection3(TwinPeak, 2, i2sOut, 1); // DAC R
#endif
#if SIGNAL_HARDWARE==TP_SIGNAL_IO_PIN
// Not realistic for a radio but useful for testing
AudioConnection_F32 connection4(TwinPeak, 1, i2sOut, 1); // DAC R
#endif
AudioConnection_F32 connection5(TwinPeak, 0, i2sOut, 0); // DAC L
// For test, send to queue. For real, send to receiver.
#ifdef PRINT_OUTPUT_DATA
AudioConnection_F32 connectionA(TwinPeak, 0, q1, 0);
AudioConnection_F32 connectionB(TwinPeak, 1, q2, 0);
AudioConnection_F32 connection6(TwinPeak, 0, q1, 0);
AudioConnection_F32 connection7(TwinPeak, 1, q2, 0);
#endif
void setup(void) {
AudioMemory_F32(30, audio_settings);
uint32_t tMillis = millis();
AudioMemory_F32(50, audio_settings);
Serial.begin(100); // Any rate
delay(500);
Serial.println("Twin Peaks L-R Synchronizer Test");
@ -84,84 +97,48 @@ void setup(void) {
Serial.println("Using I/O pin for cross-correlation test signal.");
#endif
TwinPeak.setThreshold(TP_THRESHOLD);
//TwinPeak.setThreshold(TP_THRESHOLD); Not used
TwinPeak.stateAlignLR(TP_MEASURE); // Comes up TP_IDLE
Serial.println("");
Serial.println("Update ------- Outputs -------");
Serial.println("Number -1 0 1 Shift Error");// Column headings
}
void loop(void) {
// The following, under PRINT_OUTPUT_DATA, is an output of the L & R channels
// suitable for examination in a spreadsheet.
#ifdef PRINT_OUTPUT_DATA
static int32_t ii=0;
if(ii==5)
{
q1.begin();
q2.begin();
}
if(ii>5 && ii<15)
{
if(q1.available())
{
Serial.println(" ====================");
float* pf1 = q1.readBuffer();
for(int mm=0; mm<128; mm++)
Serial.println(*(pf1 + mm),5);
q1.freeBuffer();
}
Serial.println("^--L");
if(q2.available())
{
float* pf2 = q2.readBuffer();
for(int mm=0; mm<128; mm++)
Serial.println(*(pf2 + mm),5);
q2.freeBuffer();
}
Serial.println("^--R");
}
if(ii==16)
#if SIGNAL_HARDWARE==TP_SIGNAL_IO_PIN
twoPeriods = (uint32_t)(0.5f + (2000000.0f / sample_rate_Hz));
// Note that for this hardware, the INO is 100% in charge of the PIN_FOR_TP
pData = TwinPeak.read(); // Base data to check error
while (pData->TPerror < 0 && millis()-tMillis < 2000) // with timeout
{
q1.end();
q2.end();
ii++;
if(micros()-timeSquareWave >= twoPeriods && pData->TPstate==TP_MEASURE)
{
static uint16_t squareWave = 0;
timeSquareWave = micros();
squareWave = squareWave^1;
digitalWrite(PIN_FOR_TP, squareWave);
}
pData = TwinPeak.read();
}
#endif
// uint32_t tt=micros();
TPinfo* pData = TwinPeak.read();
if(pData->nMeas > nMeasLast && pData->nMeas<20)
{
nMeasLast = pData->nMeas; // This print takes about 6 microseconds
Serial.print(pData->nMeas); Serial.print(", ");
// The update has moved from Measure to Run. Ground the PIN_FOR_TP
//TwinPeak.stateAlignLR(TP_RUN); // TP is done, not TP_MEASURE
digitalWrite(PIN_FOR_TP, 0); // Set pin to zero
Serial.println("");
Serial.println("Update ------------ Outputs ------------");
Serial.println("Number xNorm -1 0 1 Shift Error State");// Column headings
Serial.print(pData->nMeas); Serial.print(", ");
Serial.print(pData->xNorm, 6); Serial.print(", ");
Serial.print(pData->xcVal[3], 6); Serial.print(", ");
Serial.print(pData->xcVal[0], 6); Serial.print(", ");
Serial.print(pData->xcVal[1], 6); Serial.print(", ");
Serial.print(pData->neededShift); Serial.print(", ");
Serial.println(pData->TPerror);
//Serial.println(pData->TPstate);
#if SIGNAL_HARDWARE==TP_SIGNAL_IO_PIN
if(pData->TPerror == 0)
{
TwinPeak.stateAlignLR(TP_RUN); // TP is done
digitalWrite(PIN_FOR_TP, 0);
}
#endif
// Serial.println(micros()-tt);
}
Serial.print(pData->TPerror); Serial.print(", ");
Serial.println(pData->TPstate);
#if SIGNAL_HARDWARE==TP_SIGNAL_IO_PIN
// Generate 11.11 kHz square wave
// For other sample rates, set to roughly 2 sample periods, in microseconds
if(micros()-timeSquareWave >= 45 && pData->TPstate==TP_MEASURE)
{
static uint16_t squareWave = 0;
timeSquareWave = micros();
squareWave = squareWave^1;
digitalWrite(PIN_FOR_TP, squareWave);
}
// You can see the injected signal level by the printed variable, pData->xNorm
// It is the sum of the 4 cross-correlation numbers and if it is below 0.0001 the
// measurement is getting noisy and un-reliable. Raise the injected signal level
// to solve the problem.
#endif
}
void loop(void) {
}

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