Mercurial > hg > beaglert
diff examples/02-Digital/digital-output/render.cpp @ 464:8fcfbfb32aa0 prerelease
Examples reorder with subdirectories. Added header to each project. Moved Doxygen to bottom of render.cpp.
author | Robert Jack <robert.h.jack@gmail.com> |
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date | Mon, 20 Jun 2016 16:20:38 +0100 |
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children | b935f890e512 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/examples/02-Digital/digital-output/render.cpp Mon Jun 20 16:20:38 2016 +0100 @@ -0,0 +1,89 @@ +/* + ____ _____ _ _ +| __ )| ____| | / \ +| _ \| _| | | / _ \ +| |_) | |___| |___ / ___ \ +|____/|_____|_____/_/ \_\ + +The platform for ultra-low latency audio and sensor processing + +http://bela.io + +A project of the Augmented Instruments Laboratory within the +Centre for Digital Music at Queen Mary University of London. +http://www.eecs.qmul.ac.uk/~andrewm + +(c) 2016 Augmented Instruments Laboratory: Andrew McPherson, + Astrid Bin, Liam Donovan, Christian Heinrichs, Robert Jack, + Giulio Moro, Laurel Pardue, Victor Zappi. All rights reserved. + +The Bela software is distributed under the GNU Lesser General Public License +(LGPL 3.0), available here: https://www.gnu.org/licenses/lgpl-3.0.txt +*/ + + +#include <Bela.h> +#include <cmath> +#include <rtdk.h> + +bool setup(BelaContext *context, void *userData) +{ + pinMode(context, 0, P8_07, OUTPUT); + return true; +} + +void render(BelaContext *context, void *userData) +{ + static int count=0; //counts elapsed samples + float interval=0.5; //how often to toggle the LED (in seconds) + static int status=GPIO_LOW; + for(unsigned int n=0; n<context->digitalFrames; n++){ + if(count==context->digitalSampleRate*interval){ //if enough samples have elapsed + count=0; //reset the counter + // status=digitalRead(context, 0, P8_07); + if(status==GPIO_LOW) { //toggle the status + digitalWrite(context, n, P8_07, status); //write the status to the LED + status=GPIO_HIGH; + } + else { + digitalWrite(context, n, P8_07, status); //write the status to the LED + status=GPIO_LOW; + } + } + count++; + } +} + +void cleanup(BelaContext *context, void *userData) +{ + // Nothing to do here +} + +/* ------------ Project Explantation ------------ */ + +/** +\example 02-digital-output + +Blinking an LED +--------------- + +This sketch shows the simplest case of digital out. + +- Connect an LED in series with a 470ohm resistor between P8_07 and ground. + +The led is blinked on and off by setting the digital pin `HIGH` and `LOW` every interval seconds which is set in +`render()`. + +In `setup()` the pin mode must be set to output mode via `pinMode()`. For example: +`pinMode(context, 0, P8_07, OUTPUT)`. +In `render()` the output of the digital pins is set by `digitalWrite()`. For example: +`digitalWrite(context, n, P8_07, status)` where `status` can be equal to +either `HIGH` or `LOW`. When set `HIGH` the pin will give 3.3V, when set to +`LOW` 0V. + +To keep track of elapsed time we have a sample counter count. When the count reaches +a certain limit it switches state to either `HIGH` or `LOW` depending on its current +value. In this case the limit is `context->digitalSampleRate*interval` which +allows us to write the desired interval in seconds, stored in `interval`. +*/ +