Mercurial > hg > beaglert
diff examples/analogDigitalDemo/render.cpp @ 300:dbeed520b014 prerelease
Renamed projects to examples
author | Giulio Moro <giuliomoro@yahoo.it> |
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date | Fri, 27 May 2016 13:58:20 +0100 |
parents | projects/analogDigitalDemo/render.cpp@567bd8f76714 |
children | e4392164b458 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/examples/analogDigitalDemo/render.cpp Fri May 27 13:58:20 2016 +0100 @@ -0,0 +1,94 @@ + /* + * + * 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 + * */ +{ + /* + * TODO: as an exercise, you will need to set the pin mode before writing or reading the digital pins. + */ + 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 +}