Diff: Receiver.cpp

Revision:

4:a3c4a43f94f8

Child:

6:ac7c0ccf9b5d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Receiver.cpp	Mon Oct 23 21:18:07 2017 +0000
@@ -0,0 +1,107 @@
+#include <Receiver.h>
+
+
+InterruptIn DO(p21);
+
+const int us_period = 10000;
+
+void ReceiverData::setTime()
+{
+    lastTime = time.read_us();
+}
+
+void ReceiverData::addBit(unsigned char bit)
+{
+    setTime();
+    if(bit != 0)
+    {
+        // MSB First
+        temp = temp | 1 << (7-currentBit);
+    }
+    
+    currentBit++;
+
+    // If filled  a whole byte, send it to the data
+    if(currentBit == 8) {
+        data.push_back(temp);        
+        temp = 0;
+        currentBit = 0;
+    }
+}
+
+void ReceiverData::clear()
+{
+    currentBit =0;
+    lastTime =0;
+    temp =0;
+    data.clear();
+    time.stop();    
+}
+
+
+void ReceiverData::fall()
+{
+    if(!ready){
+        return;
+    }
+    
+    if(waiting()) {
+        //First data is a 0 (rising edge)
+        return;
+    }
+    if(time.read_us() - lastTime < us_period/2) {
+        // This transition is not real data.
+        return;
+    } else {
+        addBit(1);
+    }
+}
+
+void ReceiverData::rise()
+{
+    if(!ready){
+        return;
+    }
+    
+    if(waiting()) {
+        // Should be the first 0 in the first byte
+        receiving = true;
+        addBit(0);
+        return;
+    }
+
+    if(time.read_us() - lastTime < us_period/2) {
+        // This transition is not real data.
+        return;
+    } else {
+        addBit(0);
+    }
+}
+
+void ReceiverData::waitData()
+{
+    dataSemaphore.wait();
+}
+
+void ReceiverData::timeout()
+{
+    if(!receiving){
+        return;
+    }
+    if(time.read_us() - lastTime > 3/2 * us_period )
+    {   // Finished
+        dataSemaphore.release();
+        
+        watchDog.detach();
+        ready = false;
+    }
+}
+
+void ReceiverData::start()
+{
+    clear();
+    DO.fall(this,&ReceiverData::fall);
+    DO.rise(this, &ReceiverData::rise);
+    watchDog.attach(this, &ReceiverData::timeout,us_period);
+    ready = true;
+}
\ No newline at end of file