changeset 206:0ec86af13cd1

Added PulseIn example

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/projects/basic_pulseIn/render.cpp	Sat Feb 06 12:26:59 2016 +0000
@@ -0,0 +1,73 @@
+/*
+ * render.cpp
+ *
+ *  Created on: Oct 24, 2014
+ *      Author: parallels
+ */
+
+#include <BeagleRT.h>
+#include <PulseIn.h>
+#include <Utilities.h>
+#include <stdlib.h>
+#include <rtdk.h>
+#include <cmath>
+
+// setup() is called once before the audio rendering starts.
+// Use it to perform any initialisation and allocation which is dependent
+// on the period size or sample rate.
+//
+// userData holds an opaque pointer to a data structure that was passed
+// in from the call to initAudio().
+//
+// Return true on success; returning false halts the program.
+PulseIn pulseIn;
+int gPulseInPin = 0;
+int gDigitalOutPin = 1;
+int gPulseLength = 1234;
+int gSamplesBetweenPulses = 10000;
+
+bool setup(BeagleRTContext *context, void *userData)
+{
+	pinModeFrame(context, 0, gDigitalOutPin, OUTPUT);
+	pulseIn.init(context, gPulseInPin, 1); //third parameter is direction
+	return true;
+}
+
+// render() is called regularly at the highest priority by the audio engine.
+// Input and output are given from the audio hardware and the other
+// ADCs and DACs (if available). If only audio is available, numMatrixFrames
+// will be 0.
+
+void render(BeagleRTContext *context, void *userData)
+{
+	static bool pulseOut = 0;
+	static int count = 0;
+	for(unsigned int n = 0; n < context->digitalFrames; n++){
+		// detect if a pulse just ended
+		int duration = pulseIn.hasPulsed(context, n);
+		if(duration > 0){
+			rt_printf("duration = %d\n", duration);
+		}
+
+		// generate a rectangular waveform as a test signal.
+		// Connect gDigitalOutPin to gPulseInPin
+		// to verify that the detected pulse length is gPulseLength
+		if(count == gPulseLength ){
+			pulseOut = false;
+		}
+		if(count == (gPulseLength + gSamplesBetweenPulses)){
+			pulseOut = true;
+			count = 0;
+		}
+		digitalWriteFrame(context, n, gDigitalOutPin, pulseOut);
+		count++;
+	}
+}
+
+// cleanup() is called once at the end, after the audio has stopped.
+// Release any resources that were allocated in setup().
+
+void cleanup(BeagleRTContext *context, void *userData)
+{
+
+}