comparison projects/analogDigitalDemo/render.cpp @ 67:472e892c6e41

Merge newapi into default

+    /*
+ *
+ * Andrew McPherson and Victor Zappi
+ * Queen Mary, University of London
+ */
+
+#include <BeagleRT.h>
+#include <Utilities.h>
+#include <cmath>
+#include <rtdk.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)
+{
+	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.
+
+void render(BeagleRTContext *context, void *userData)
+/*
+we assume that gNumAnalogChannels=8, numAnalogFrames==8 and  numDigitalFrames==numAudioFrames
+ * */
+{
+	if((context->audioSampleCount&31)==0){ //every 32 frames...
+        //ANALOG channels
+		analogWriteFrame(context, 0, 0, analogReadFrame(context, 0,0));
+		// read the input0 at frame0  and write it to output0 frame0. Using analogWrite will fill the rest of the buffer with the same value
+                                            // The value at the last frame will persist through the successive buffers until is set again.
+                                            // This effectively is a pass-through with downsampling by 32 times
+        analogWriteFrame(context, 0, 3, 1.0);  // write 1.0 to channel3 from frame0 to the end of the buffer
+        analogWriteFrame(context, 4, 3, 0.1);  // write 0.1  to channel3 from frame4 to the end of the buffer
+        analogWriteFrameOnce(context, 6, 3, 0.2); //write 0.2 to channel3 only on frame 6
+        //this buffer for channel 3 will look like this:  1 1 1 1 0.1 0.1 0.2 0.1 
+        //the next buffers for channel 3 will be filled up with 0.1 ....
+        //DIGITAL channels
+        digitalWriteFrame(context, 0, P8_07, GPIO_HIGH); //sets all the frames  to HIGH for channel 0
+        digitalWriteFrameOnce(context, 4, P8_07, GPIO_LOW); //only frame 4 will be LOW  for channel 0
+        // in this buffer the frames of channel 0 will look like this: 1 1 1 1 0 1 1 1 ...... 1 
+        // in the next buffer each frame of channel 0 will be initialized to 1 (the last value of this buffer)
+        digitalWriteFrame(context, 0, P8_08, GPIO_HIGH);
+        digitalWriteFrame(context, 2, P8_08, GPIO_LOW);
+        digitalWriteFrame(context, 4, P8_08, GPIO_HIGH);
+        digitalWriteFrame(context, 5, P8_08, GPIO_LOW);
+        pinModeFrame(context, 0, P9_16, GPIO_INPUT); // set channel 10 to input
+        // in this buffer the frames of channel 1 will look like this: 1 1 0 0 1 0 0 0 .... 0
+        // in the next buffer each frame of channel 1 will be initialized to 0 (the last value of this buffer)
+	}
+	for(unsigned int n=0; n<context->audioFrames; n++){
+		for(unsigned int c=0; c<context->audioChannels; c++){
+			context->audioOut[n*context->audioChannels + c]=context->audioIn[n*context->audioChannels + c];
+		}
+        //use digital channels 2-8 to create a 7 bit binary counter
+        context->digital[n]=context->digital[n] & (~0b111111100); // set to zero (GPIO_OUTPUT) the bits in the lower word
+        context->digital[n]=context->digital[n] & ((~0b111111100<<16) | 0xffff ); //initialize to zero the bits in the higher word (output value)
+        context->digital[n]=context->digital[n] | ( ((context->audioSampleCount&0b1111111)<<(16+2)) ) ;  // set the bits in the higher word to the desired output value, keeping the lower word unchanged
+        digitalWriteFrame(context, n, P8_29, digitalReadFrame(context, n, P8_30)); // echo the input from from channel 15 to channel 14
+        digitalWriteFrame(context, n, P8_28, digitalReadFrame(context, n, P9_16)); // echo the input from from channel 10 to channel 13
+        pinModeFrame(context, 0, P8_30, 0); //set channel 15 to input
+	}
+
+	for(unsigned int n=0; n<context->analogFrames; n++){
+    	analogWriteFrame(context, n, 1, (context->audioSampleCount&8191)/8192.0); // writes a single frame. channel 1 is a ramp that follows gCountFrames
+    	analogWriteFrame(context, n, 2, analogReadFrame(context, n, 2)); // writes a single frame. channel2 is just a passthrough
+//		rt_printf("Analog out frame %d :",n);
+//		for(int c=0; c<gNumAnalogChannels; c++)
+//			rt_printf("%.1f ",analogOut[n*gNumAnalogChannels + c]);
+//		rt_printf("\n");
+	}
+	return;
+
+}
+
+// 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
+}