bright.c 1.6 KB

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  1. /*
  2. * bright.c:
  3. * Vary the Q2W LED brightness with the analog card
  4. *
  5. * Copyright (c) 2012-2013 Gordon Henderson. <projects@drogon.net>
  6. ***********************************************************************
  7. * This file is part of wiringPi:
  8. * https://projects.drogon.net/raspberry-pi/wiringpi/
  9. *
  10. * wiringPi is free software: you can redistribute it and/or modify
  11. * it under the terms of the GNU Lesser General Public License as published by
  12. * the Free Software Foundation, either version 3 of the License, or
  13. * (at your option) any later version.
  14. *
  15. * wiringPi is distributed in the hope that it will be useful,
  16. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18. * GNU Lesser General Public License for more details.
  19. *
  20. * You should have received a copy of the GNU Lesser General Public License
  21. * along with wiringPi. If not, see <http://www.gnu.org/licenses/>.
  22. ***********************************************************************
  23. */
  24. #include <stdio.h>
  25. #include <wiringPi.h>
  26. #include <pcf8591.h>
  27. #define LED 1
  28. #define Q2W_ABASE 120
  29. int main (void)
  30. {
  31. int value ;
  32. // Enable the on-goard GPIO
  33. wiringPiSetup () ;
  34. // Add in the pcf8591 on the q2w board
  35. pcf8591Setup (Q2W_ABASE, 0x48) ;
  36. printf ("Raspberry Pi - Quick2Wire Analog Test\n") ;
  37. // Setup the LED
  38. pinMode (LED, PWM_OUTPUT) ;
  39. pwmWrite (LED, 0) ;
  40. for (;;)
  41. {
  42. value = analogRead (Q2W_ABASE + 0) ;
  43. pwmWrite (LED, value * 4) ;
  44. delay (10) ;
  45. }
  46. return 0 ;
  47. }