keyboard/cluepad/backlight.c

   1 #include <avr/io.h>
   2 #include "backlight.h"
   3 #include "led.h"
   4
   5 #include "print.h"
   6
   7 int pwm_level;
   8
   9 void led_set_kb(uint8_t usb_led)
  10 {
  11     print("led_set\n");
  12 }
  13
  14 void init_backlight_pin(void)
  15 {
  16     // Set C7 to output
  17     DDRC |= (1<<7);
  18
  19     // Initialize the timer
  20     TC4H = 0x03;
  21     OCR4C = 0xFF;
  22     TCCR4A = 0b10000010;
  23     TCCR4B = 0b00000001;
  24 }
  25
  26 void backlight_set(uint8_t level)
  27 {
  28     // Determine the PWM level
  29     switch (level)
  30     {
  31         case 0:
  32             // 33%
  33             pwm_level = 0x54;
  34             break;
  35         case 1:
  36             // 66%
  37             pwm_level = 0xA8;
  38             break;
  39         case 2:
  40             // 100%
  41             pwm_level = 0xFF;
  42             break;
  43         case 3:
  44             // 0%
  45             pwm_level = 0x00;
  46             break;
  47         default:
  48             xprintf("Unknown level: %d\n", level);
  49     }
  50
  51     // Write the PWM level to the timer
  52     TC4H = pwm_level >> 8;
  53     OCR4A = 0xFF & pwm_level;
  54 }