/* * softTone.c: * For that authentic retro sound... * Er... A little experiment to produce tones out of a Pi using * one (or 2) GPIO pins and a piezeo "speaker" element. * (Or a high impedance speaker, but don'y blame me if you blow-up * the GPIO pins!) * Copyright (c) 2012 Gordon Henderson *********************************************************************** * This file is part of wiringPi: * https://github.com/WiringPi/WiringPi/ * * wiringPi is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * wiringPi is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with wiringPi. * If not, see . *********************************************************************** */ #ifdef __cplusplus extern "C" { #endif extern int softToneCreate (int pin) ; extern void softToneStop (int pin) ; extern void softToneWrite (int pin, int freq) ; #ifdef __cplusplus } #endif