Final version of the real-time receiver

src/diode_calibration/diode_calibration.h

@@ -1,3 +1,6 @@
+#ifndef CALIBRATION
+#define CALIBRATION
+
 #include "Arduino.h"
 #include <vector>
 #include <algorithm>
@@ -186,4 +189,6 @@ class LightIntensityRegulator {
       }
       return read_sum / window;
     }
-};
+};
+
+#endif

src/main.cpp

@@ -26,22 +26,37 @@ void plotter() {
 
 void setup() {
   Serial.begin(9600);
-  //while(!Serial);
+  while(!Serial);
 
   // Start visualization thread. Comment out if no visualization/data_collection is required
-  plotter_thread.start(plotter);
+  // plotter_thread.start(plotter);
 
   // Setup the lightintensity regulator.
   regulator = new LightIntensityRegulator();
 
-  //tensorflowSetup();
-  //receiverSetup();
+  // tensorflowSetup();
+  receiverSetup([]{regulator->resistorDown();}, []{regulator->resistorUp();});
+
+  // pinMode(A0, ANALOG);
+  // pinMode(A1, INPUT);
+  // pinMode(A2, INPUT);
 }
 
 
 void loop() {
 
 
-  //receiverLoop();
+    // int r0 = analogRead(A0);
+    // int r1 = analogRead(A1);
+    // int r2 = analogRead(A2);
+
+    // Serial.print(r0);
+    // Serial.print(", ");
+    // Serial.print(r1);
+    // Serial.print(", ");
+    // Serial.println(r2);
+    // delay(10);
+
+    receiverLoop();
 
 }

src/receiver/GRDiodeReader.h

@@ -1,5 +1,7 @@
 #include<inttypes.h>
 
+#include "receiver-parameters.h"
+
 /**
  * @brief A class abstracting the reading of sensors and storing their input.
  * 
@@ -12,4 +14,12 @@ class GRDiodeReader {
         void read(uint8_t d, uint16_t * dest) {
             *dest = analogRead(d);
         }
+
+        template<int size> 
+        void readAll(uint16_t dest[NUM_PDs][size],int index) {
+            for (size_t i = 0; i < NUM_PDs; i++)
+            {
+                this->read(pds[i], &dest[i][index]);
+            }
+        }
 };

src/receiver/GRPreprocessingPipeline.h

@@ -47,10 +47,10 @@ class GRPreprocessingPipeline {
         bool trimmed = false;
         int trimCount = 0;
         int i = gestureSignalLength;
-        while(i-- >= 0 && trimCount++ < DETECTION_END_WINDOW_LENGTH * DETECTION_END_WINDOW_TRIM) {
+        while(i-- >= 0) {
             bool zero = true;
             for (size_t di = 0; di < NUM_PDs; di++)
-                zero = zero && (rawData[di][i] <= 1);
+                zero = zero && (rawData[di][i] == 0);
 
             if (zero) {
                 trimmed = true;
@@ -72,7 +72,7 @@ class GRPreprocessingPipeline {
         for (size_t i = 0; i < NUM_PDs; i++)
         {
             fftFilter[i].ZeroImag();
-            fftFilter[i].Filter(rawData[i], gestureSignalLength, 5, 1000 / READ_PERIOD);
+            fftFilter[i].Filter(rawData[i], gestureSignalLength, 10, 1000 / READ_PERIOD);
             fftFilter[i].MoveDataToBufferF(photodiodeDataFFTFiltered[i]);
         }
 
@@ -81,6 +81,21 @@ class GRPreprocessingPipeline {
         FOR(di, i, NUM_PDs, gestureSignalLength, 
             photodiodeDataFFTFiltered[di][i] = max(0, photodiodeDataFFTFiltered[di][i] - thresholds[di] * CUTT_OFF_THRESHOLD_COEFF_POST_FFT);
         );
+
+        trimmed = false;
+        trimCount = 0;
+        i = gestureSignalLength;
+        while(i-- >= 0) {
+            bool zero = true;
+            for (size_t di = 0; di < NUM_PDs; di++)
+                zero = zero && (photodiodeDataFFTFiltered[di][i] == 0);
+
+            if (zero) {
+                trimmed = true;
+                gestureSignalLength--;
+            }
+        }
+        if(trimmed) gestureSignalLength++;
 
         #ifdef PLOT_RECEIVER
             sendSignal(photodiodeDataFFTFiltered, FFT_SIGNAL_LENGTH);

src/receiver/README.md

@@ -0,0 +1,32 @@
+# Real-time Photodiode (PD) - based Gesture Receiver
+
+## Directory Structure
+- [receiver.hpp](receiver.hpp) : receiver main file, containing its FSM architecture
+
+- [receiver-parameters.h](receiver-parameters.h) : various macros and photodiode pins setups for use by the rest of the files   
+
+- [receiver-util.h](receiver-util.h) : auxiliary utility macros and functions
+
+- [GRDiodeReader.h](GRDiodeReader.h) : abstraction over PD reading. Used in [receiver.hpp](receiver.hpp).
+
+- [GREdgeDetector.h](GREdgeDetector.h) : abstraction over checking for gesture start and end using an adjustable threshold. Used in [receiver.hpp](receiver.hpp).
+
+- [GRPreprocessingPipeline.h](GRPreprocessingPipeline.h) + [pipeline-stages/](pipeline-stages/) : pipeline for noise reduction and normalisation of gesture data. Used in [receiver.hpp](receiver.hpp).
+
+- [plotting/](plotting/) : auxiliary files for plotting the output of the preprocessing pipeline stages.
+
+
+## Plotting the receiver pipeline stages' outputs:
+
+* Go to `receiver-parameters.h` and uncomment the `PLOT_RECEIVER` macro.
+* After starting the system on the Arduino connected via a serial port, run the Python script [plotter.py](plotting/plotter.py).
+
+## Debugging the receiver main FSM:
+
+* Go to `receiver-parameters.h` and uncomment the `DEBUG_RECEIVER` macro.
+* Start the system on the Arduino connected via a serial port and monitor the port input.
+
+## Turning off hardware adjustment and only using software threshold adjustment
+
+* Go to `receiver-parameters.h` and uncomment the `NO_HARDWARE_ADJUSTMENT` macro.
+

src/receiver/receiver-parameters.h

@@ -23,6 +23,7 @@
 #define GESTURE_BUFFER_LENGTH           500
 // Buffer for threshold adjustment
 #define THRESHOLD_ADJ_BUFFER_LENGTH     100
+#define THRESHOLD_UPD_BUFFER_LENGTH     20
 
 // Sampling period and minimum expected gesture duration
 #define READ_PERIOD                     10
@@ -53,6 +54,7 @@
     };
 
 // #define DEBUG_RECEIVER
+// #define NO_HARDWARE_ADJUSTMENT
 // #define PLOT_RECEIVER
 
 #endif