diff projects/basic_analog_output/render.cpp @ 12:a6beeba3a648

Initial support for higher matrix sample rates by reducing the number of channels. Input not tested yet, and not all examples updated to new format.

--- a/projects/basic_analog_output/render.cpp	Thu Nov 13 16:02:59 2014 +0100
+++ b/projects/basic_analog_output/render.cpp	Thu Jan 22 19:00:22 2015 +0000
@@ -19,6 +19,8 @@
 float gPhase;
 float gInverseSampleRate;
 
+int gMatrixChannels;
+
 // initialise_render() 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.
@@ -28,19 +30,22 @@
 //
 // Return true on success; returning false halts the program.
 
-bool initialise_render(int numChannels, int numMatrixFramesPerPeriod,
-					   int numAudioFramesPerPeriod, float matrixSampleRate,
-					   float audioSampleRate, void *userData)
+bool initialise_render(int numMatrixChannels, int numAudioChannels,
+					   int numMatrixFramesPerPeriod,
+					   int numAudioFramesPerPeriod,
+					   float matrixSampleRate, float audioSampleRate,
+					   void *userData)
 {
 	// Retrieve a parameter passed in from the initAudio() call
 	gFrequency = *(float *)userData;
 
-	if(numMatrixFramesPerPeriod*2 != numAudioFramesPerPeriod) {
-		rt_printf("Error: this example needs the matrix enabled, running at half audio rate\n");
+	if(numMatrixFramesPerPeriod == 0) {
+		rt_printf("Error: this example needs the matrix enabled\n");
 		return false;
 	}
 
-	gInverseSampleRate = 1.0 / audioSampleRate;
+	gMatrixChannels = numMatrixChannels;
+	gInverseSampleRate = 1.0 / matrixSampleRate;
 	gPhase = 0.0;
 
 	return true;
@@ -57,12 +62,13 @@
 	for(int n = 0; n < numMatrixFrames; n++) {
 		// Set LED to different phase for each matrix channel
 		float relativePhase = 0.0;
-		for(int channel = 0; channel < 8; channel++) {
+		for(int channel = 0; channel < gMatrixChannels; channel++) {
 			float out = kMinimumAmplitude + kAmplitudeRange * 0.5f * (1.0f + sinf(gPhase + relativePhase));
 			if(out > MATRIX_MAX)
 				out = MATRIX_MAX;
 
-			analogWrite(channel, n, out);
+			matrixOut[n * gMatrixChannels + channel] = (uint16_t)out;
+			//analogWrite(channel, n, out);
 
 			// Advance by pi/4 (1/8 of a full rotation) for each channel
 			relativePhase += M_PI * 0.25;