robert@464: /*
robert@464:  ____  _____ _        _    
robert@464: | __ )| ____| |      / \   
robert@464: |  _ \|  _| | |     / _ \  
robert@464: | |_) | |___| |___ / ___ \ 
robert@464: |____/|_____|_____/_/   \_\
robert@464: 
robert@464: The platform for ultra-low latency audio and sensor processing
robert@464: 
robert@464: http://bela.io
robert@464: 
robert@464: A project of the Augmented Instruments Laboratory within the
robert@464: Centre for Digital Music at Queen Mary University of London.
robert@464: http://www.eecs.qmul.ac.uk/~andrewm
robert@464: 
robert@464: (c) 2016 Augmented Instruments Laboratory: Andrew McPherson,
robert@464: 	Astrid Bin, Liam Donovan, Christian Heinrichs, Robert Jack,
robert@464: 	Giulio Moro, Laurel Pardue, Victor Zappi. All rights reserved.
robert@464: 
robert@464: The Bela software is distributed under the GNU Lesser General Public License
robert@464: (LGPL 3.0), available here: https://www.gnu.org/licenses/lgpl-3.0.txt
robert@464: */
robert@464: 
robert@464: 
robert@464: #include <Bela.h>
robert@464: #include <cmath>
robert@464: #include <rtdk.h>
robert@464: #include <stdlib.h>
robert@464: 
robert@464: 
robert@464: bool setup(BelaContext *context, void *userData)
robert@464: {
robert@464: 	pinMode(context, 0, P8_08, INPUT);
robert@464: 	pinMode(context, 0, P8_07, OUTPUT);
robert@464: 	return true;
robert@464: }
robert@464: 
robert@464: 
robert@464: void render(BelaContext *context, void *userData)
robert@464: {
robert@464: 	for(unsigned int n=0; n<context->digitalFrames; n++){
robert@464: 		int status=digitalRead(context, 0, P8_08); //read the value of the button
robert@464: 		digitalWriteOnce(context, n, P8_07, status); //write the status to the LED
robert@464: 		float out = 0.1 * status * rand() / (float)RAND_MAX * 2 - 1; //generate some noise, gated by the button
robert@464: 		for(unsigned int j = 0; j < context->audioChannels; j++){
robert@464: 			audioWrite(context, n, j, out); //write the audio output
robert@464: 		}
robert@464: 	}
robert@464: }
robert@464: 
robert@464: 
robert@464: void cleanup(BelaContext *context, void *userData)
robert@464: {
robert@464: 	// Nothing to do here
robert@464: }
robert@464: 
robert@464: 
robert@464: /**
robert@500: \example digital-input/render.cpp
robert@464: 
robert@464: Switching an LED on and off
robert@464: ---------------------------
robert@464: 
robert@464: This example brings together digital input and digital output. The program will read 
robert@464: a button and turn the LED on and off according to the state of the button.
robert@464: 
robert@464: - connect an LED in series with a 470ohm resistor between P8_07 and ground.
robert@464: - connect a 1k resistor to P9_03 (+3.3V),
robert@464: - connect the other end of the resistor to both a button and P8_08
robert@464: - connect the other end of the button to ground.
robert@464: 
robert@464: You will notice that the LED will normally stay on and will turn off as long as 
robert@464: the button is pressed. This is due to the fact that the LED is set to the same 
robert@464: value read at input P8_08. When the button is not pressed, P8_08 is `HIGH` and so 
robert@464: P8_07 is set to `HIGH` as well, so that the LED conducts and emits light. When 
robert@464: the button is pressed, P8_08 goes `LOW` and P8_07 is set to `LOW`, turning off the LED.
robert@464: 
robert@464: As an exercise try and change the code so that the LED only turns on when 
robert@464: the button is pressed.
robert@464: */
robert@464: