Diff: main.cpp

Revision:

4:037345932888

Parent:

3:1235cbe67ec9

Child:

5:fc3ce1c5db88

--- a/main.cpp	Sun Nov 08 00:45:49 2015 +0000
+++ b/main.cpp	Sun Nov 08 02:36:11 2015 +0000
@@ -4,8 +4,9 @@
 
 Serial pc(USBTX, USBRX); // tx, rx
 
-static const int N_PPM = 4;
-static const int PULSE_TIME = 10000;
+static const int PPM_BITS = 2;
+static const int N_PPM = 1 << PPM_BITS;
+static const int PULSE_TIME = 1000;
 static const int SAMPLE_RATE = 10; // must be a divisor of PULSE_TIME
 static const int SAMPLE_GAP = PULSE_TIME / SAMPLE_RATE;
 static const int HALF_SAMPLE = SAMPLE_RATE / 2;
@@ -19,19 +20,34 @@
 bool sample_lock = false;
 int offCount, onCount;
 
-char* decodechar(int stopIdx){
+void printDecode(int stopIdx){
+
     int len = (stopIdx - start + BUF_SIZE) % BUF_SIZE;
-    bool* data = new bool[len * N_PPM];
+    int size = PPM_BITS * len / 8 + 1;
+    char data[size];
+    for(int i = 0; i < size; i++) data[i] = 0;
+    //pc.printf("\r\nDecode: ");
+    int k = 0;
     for(int i = 0; i < len; i++)
     {
         int c = buf[start++];
         if(start == BUF_SIZE) start = 0;
-        for(int j = 0; j < N_PPM; j++)
+        for(int j = 0; j < PPM_BITS; j++)
         {
-            data[i * N_PPM + j] = (c >> (N_PPM - j - 1));
+            bool bit = (c >> (PPM_BITS - j - 1)) & 1;
+            if(k%8 == 0) data[k/8] = 0;
+            data[k/8] |= bit << (7 - k%8);
+            k++;
+            //pc.printf("%d", bit);
         }
     }
-    return (char*) data;
+    pc.printf("Received: \"");
+    pc.printf(data);
+    pc.printf("\"\r\n");
+    if(start != stopIdx)
+    {
+        pc.printf("\r\nWarning: Incomplete byte\r\n");
+    }
 }
 
 void sample()
@@ -43,16 +59,15 @@
         offCount++;
         if(onCount > HALF_SAMPLE)
         {
-            pc.printf("0:%d ", onCount);
             onCount = 0;
         }
     }else{ // Pulse
         if(offCount > HALF_SAMPLE)
         {
             int offPulses = (offCount + HALF_SAMPLE) / SAMPLE_RATE - 1;
-            pc.printf("1:%d:%d ", offCount, offPulses);
             if(offPulses <= N_PPM)
             {
+                //pc.printf("%d ", offPulses);
                 buf[idx] = offPulses;
                 idx++;
                 if(idx == BUF_SIZE) idx = 0;
@@ -68,6 +83,7 @@
 int main()
 {
     pc.printf("3 CM Link Board - Recieve\r\n");
+    /*
     bool calib = true;
     if(calib){
         while(true){
@@ -79,23 +95,14 @@
     idx = 0;
     offCount = 0;
     offCount = 0;
-    pc.printf("Ready.\r\n");
-    float v = rx.read();
-    while(v < THRESH)
-    {
-        v = rx.read();
-        wait_us(SAMPLE_GAP);
-    }
-    pc.printf("Starting...\r\n");
+    //*/
     Ticker sampler;
     sampler.attach_us(&sample, SAMPLE_GAP);
     
     while(true){
-        if((offCount + HALF_SAMPLE) / SAMPLE_RATE > N_PPM){ // synchronize
-            char* data = decodechar(idx);
-            pc.printf(data);
-            delete[] data;
-            offCount = 0;
+        if((offCount + HALF_SAMPLE) / SAMPLE_RATE > N_PPM && start != idx){ // synchronize
+            printDecode(idx);
         }
+        wait_us(PULSE_TIME);
     }
 }
\ No newline at end of file