xdsopl/robot36
1
0
Fork 0
mirror of https://github.com/xdsopl/robot36.git synced 2025-12-06 07:12:07 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity

mark correlation peak if possible

Browse source
This commit is contained in:
Ahmet Inan 2024-04-16 15:32:52 +02:00
parent 8a1d7ca7ba
commit d207823011
2 changed files with 29 additions and 14 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

31
app/src/main/java/xdsopl/robot36/Demodulator.java
View file

@ -18,6 +18,10 @@ public class Demodulator {
private final Phasor baseBandOscillator; private final Phasor baseBandOscillator;
private final Delay syncPulseDelay; private final Delay syncPulseDelay;
private final Delay scanLineDelay; private final Delay scanLineDelay;
private final int syncPulseSamples;
private float syncPulseMaxLevel;
private int syncPulseMaxPosition;
private int syncPulseCounter;
private Complex baseBand; private Complex baseBand;
private Complex syncPulse; private Complex syncPulse;
private Complex scanLine; private Complex scanLine;
@ -34,8 +38,8 @@ public class Demodulator {
int scanLineFilterSamples = (int) Math.round(0.443 * sampleRate / scanLineCutoff) | 1; int scanLineFilterSamples = (int) Math.round(0.443 * sampleRate / scanLineCutoff) | 1;
scanLineFilter = new ComplexMovingAverage(scanLineFilterSamples); scanLineFilter = new ComplexMovingAverage(scanLineFilterSamples);
double syncPulseSeconds = 0.009; double syncPulseSeconds = 0.009;
int syncPulseFilterSamples = (int) Math.round(syncPulseSeconds * sampleRate) | 1; syncPulseSamples = (int) Math.round(syncPulseSeconds * sampleRate) | 1;
syncPulseFilter = new ComplexMovingAverage(syncPulseFilterSamples); syncPulseFilter = new ComplexMovingAverage(syncPulseSamples);
float lowestFrequency = 1100; float lowestFrequency = 1100;
float highestFrequency = 2300; float highestFrequency = 2300;
float cutoffFrequency = (highestFrequency - lowestFrequency) / 2; float cutoffFrequency = (highestFrequency - lowestFrequency) / 2;
@ -49,7 +53,7 @@ public class Demodulator {
scanLineOscillator = new Phasor(-(grayFrequency - centerFrequency), sampleRate); scanLineOscillator = new Phasor(-(grayFrequency - centerFrequency), sampleRate);
int syncPulseDelaySamples = (powerWindowSamples - 1) / 2; int syncPulseDelaySamples = (powerWindowSamples - 1) / 2;
syncPulseDelay = new Delay(syncPulseDelaySamples); syncPulseDelay = new Delay(syncPulseDelaySamples);
int scanLineDelaySamples = (powerWindowSamples - 1) / 2 + (syncPulseFilterSamples - 1) / 2 - (scanLineFilterSamples - 1) / 2; int scanLineDelaySamples = (powerWindowSamples - 1) / 2 + (syncPulseSamples - 1) / 2 - (scanLineFilterSamples - 1) / 2;
scanLineDelay = new Delay(scanLineDelaySamples); scanLineDelay = new Delay(scanLineDelaySamples);
syncPulseTrigger = new SchmittTrigger(0.17f, 0.19f); syncPulseTrigger = new SchmittTrigger(0.17f, 0.19f);
baseBand = new Complex(); baseBand = new Complex();
@ -66,10 +70,25 @@ public class Demodulator {
float scanLineValue = scanLineDelay.push(scanLineDemod.demod(scanLine)); float scanLineValue = scanLineDelay.push(scanLineDemod.demod(scanLine));
float syncPulseLevel = Math.min(Math.max(syncPulseValue, 0), 1); float syncPulseLevel = Math.min(Math.max(syncPulseValue, 0), 1);
float scanLineLevel = Math.min(Math.max(0.5f * (scanLineValue + 1), 0), 1); float scanLineLevel = Math.min(Math.max(0.5f * (scanLineValue + 1), 0), 1);
if (syncPulseTrigger.latch(syncPulseLevel)) if (syncPulseTrigger.latch(syncPulseLevel)) {
buffer[i] = -syncPulseLevel; if (syncPulseMaxLevel < syncPulseLevel) {
else syncPulseMaxLevel = syncPulseLevel;
syncPulseMaxPosition = syncPulseCounter;
}
++syncPulseCounter;
buffer[i] = syncPulseLevel;
} else if (syncPulseCounter > 0 && syncPulseCounter < syncPulseSamples) {
int offset = syncPulseCounter - syncPulseMaxPosition;
if (offset <= i)
buffer[i - offset] = -1;
syncPulseCounter = 0;
syncPulseMaxLevel = 0;
buffer[i] = scanLineLevel; buffer[i] = scanLineLevel;
} else {
syncPulseCounter = 0;
syncPulseMaxLevel = 0;
buffer[i] = scanLineLevel;
}
} }
} }
} }

12
app/src/main/java/xdsopl/robot36/MainActivity.java
View file

@ -62,15 +62,11 @@ public class MainActivity extends AppCompatActivity {
private void visualizeSignal() { private void visualizeSignal() {
for (float v : recordBuffer) { for (float v : recordBuffer) {
int pixelColor = 0x00010101; int pixelColor = 0xff00ff00;
float level = v; if (v >= 0) {
if (v < 0) { int intensity = (int) Math.round(255 * Math.sqrt(v));
level = -v; pixelColor = 0xff000000 | 0x00010101 * intensity;
pixelColor = 0x00000100;
} }
int intensity = (int) Math.round(255 * Math.sqrt(level));
pixelColor *= intensity;
pixelColor |= 0xff000000;
scopePixels[scopeWidth * curLine + curColumn] = pixelColor; scopePixels[scopeWidth * curLine + curColumn] = pixelColor;
if (++curColumn >= scopeWidth) { if (++curColumn >= scopeWidth) {
curColumn = 0; curColumn = 0;