Mercurial > hg > beaglert
diff examples/02-Digital/digital-input/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> |
---|---|
date | Mon, 20 Jun 2016 16:20:38 +0100 |
parents | |
children | b935f890e512 |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/examples/02-Digital/digital-input/render.cpp Mon Jun 20 16:20:38 2016 +0100 @@ -0,0 +1,82 @@ +/* + ____ _____ _ _ +| __ )| ____| | / \ +| _ \| _| | | / _ \ +| |_) | |___| |___ / ___ \ +|____/|_____|_____/_/ \_\ + +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> +#include <stdlib.h> + + +bool setup(BelaContext *context, void *userData) +{ + pinMode(context, 0, P8_08, INPUT); + pinMode(context, 0, P8_07, OUTPUT); + return true; +} + + +void render(BelaContext *context, void *userData) +{ + for(unsigned int n=0; n<context->digitalFrames; n++){ + int status=digitalRead(context, 0, P8_08); //read the value of the button + digitalWriteOnce(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++){ + audioWrite(context, n, j, out); //write the audio output + } + } +} + + +void cleanup(BelaContext *context, void *userData) +{ + // Nothing to do here +} + +/* ------------ Project Explantation ------------ */ + +/** +\example 02-digital-input + +Switching an LED on and off +--------------------------- + +This example brings together digital input and digital output. The program will read +a button and turn the LED on and off according to the state of the 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. + +You will notice that the LED will normally stay on and will turn off as long as +the button is pressed. This is due to the fact that the LED is set to the same +value read at input P8_08. When the button is not pressed, P8_08 is `HIGH` and so +P8_07 is set to `HIGH` as well, so that the LED conducts and emits light. When +the button is pressed, P8_08 goes `LOW` and P8_07 is set to `LOW`, turning off the LED. + +As an exercise try and change the code so that the LED only turns on when +the button is pressed. +*/ +