softTone.h 1.4 KB

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  1. /*
  2. * softTone.c:
  3. * For that authentic retro sound...
  4. * Er... A little experiment to produce tones out of a Pi using
  5. * one (or 2) GPIO pins and a piezeo "speaker" element.
  6. * (Or a high impedance speaker, but don'y blame me if you blow-up
  7. * the GPIO pins!)
  8. * Copyright (c) 2012 Gordon Henderson
  9. ***********************************************************************
  10. * This file is part of wiringPi:
  11. * https://projects.drogon.net/raspberry-pi/wiringpi/
  12. *
  13. * wiringPi is free software: you can redistribute it and/or modify
  14. * it under the terms of the GNU Lesser General Public License as
  15. * published by the Free Software Foundation, either version 3 of the
  16. * License, or (at your option) any later version.
  17. *
  18. * wiringPi is distributed in the hope that it will be useful,
  19. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  21. * GNU Lesser General Public License for more details.
  22. *
  23. * You should have received a copy of the GNU Lesser General Public
  24. * License along with wiringPi.
  25. * If not, see <http://www.gnu.org/licenses/>.
  26. ***********************************************************************
  27. */
  28. #ifdef __cplusplus
  29. extern "C" {
  30. #endif
  31. extern int softToneCreate (int pin) ;
  32. extern void softToneStop (int pin) ;
  33. extern void softToneWrite (int pin, int freq) ;
  34. #ifdef __cplusplus
  35. }
  36. #endif