diff examples/basic_button/render.cpp @ 300:dbeed520b014 prerelease

Renamed projects to examples

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/basic_button/render.cpp	Fri May 27 13:58:20 2016 +0100
@@ -0,0 +1,61 @@
+/*
+ *
+ * Andrew McPherson and Victor Zappi
+ * Queen Mary, University of London
+ */
+
+#include <BeagleRT.h>
+#include <Utilities.h>
+#include <cmath>
+#include <rtdk.h>
+#include <stdlib.h>
+
+// 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.
+
+bool setup(BeagleRTContext *context, void *userData)
+{
+	pinModeFrame(context, 0, P8_08, INPUT);
+	pinModeFrame(context, 0, P8_07, OUTPUT);
+	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, numAnalogFrames
+// will be 0.
+
+/* basic_button
+* - connect an LED in series with a 470ohm resistor between P8_07 and ground.
+* - connect a 1k resistor to P9_03 (+3.3V), 
+* - connect the other end of the resistor to both a button and P8_08
+* - connect the other end of the button to ground.
+* The program will read the button and make the LED blink when the button is pressed.
+*/
+
+void render(BeagleRTContext *context, void *userData)
+{
+	for(unsigned int n=0; n<context->digitalFrames; n++){
+		int status=digitalReadFrame(context, 0, P8_08); //read the value of the button
+		digitalWriteFrameOnce(context, n, P8_07, status); //write the status to the LED
+		float out = 0.1 * status * rand() / (float)RAND_MAX * 2 - 1; //generate some noise, gated by the button
+		for(unsigned int j = 0; j < context->audioChannels; j++){
+			audioWriteFrame(context, n, j, out); //write the audio output
+		}
+	}
+}
+
+// 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)
+{
+	// Nothing to do here
+}
+