ui_led.c

/*
  led.c
  
  providing control of the LEDs on the UI board since 2009.
  
  Nicolas Williamson - July 2009
  Adapted from code by Emily Lee
*/

#include <includes.h> 

#define LED_BUSY (SSPSR & (1<<4))
#define LED_TNF (SSPSR & (1<<1))
#define LED_RNE (SSPSR & (1<<2))
#define SSEL_LO FIO0CLR = (1<<20);
#define SSEL_HI FIO0SET = (1<<20);

#define R 2  // red
#define G 1  // green
#define B 0  // blue
#define NO_OP 0x2000  // no-op

void ui_led_init(void)
{
  while(!LED_TNF){}   // wait if transmit buffer is full
  SSEL_LO;
  SSPDR = 0x1001;   // configuration: run mode
  while(!LED_TNF){}   // wait if transmit buffer is full
  SSPDR = 0x1001;   // configuration: run mode
  while(LED_BUSY) {}  // wait if transfering data
  SSEL_HI;

  while(!LED_TNF){}   // wait if transmit buffer is full
  SSEL_LO;
  SSPDR = 0x0A01;       // turn off all LEDs, 16 bit
  while(!LED_TNF){}   // wait if transmit buffer is full
  SSPDR = 0x0A01;       // turn off all LEDs, 16 bit
  while(LED_BUSY) {}  // wait if transfering data
  SSEL_HI;
}

void ui_led_register_write(unsigned int device, unsigned int address, unsigned int w_data)
{
  // device 1 or 2 indicates first or second max6966 chip
  if (device == 1){
    while(!LED_TNF){}    // wait if transmit buffer is full
    SSEL_LO;        // SSEL1 low
    SSPDR = NO_OP;           // dummy data for device 2
    while(!LED_TNF){}    // wait if transmit buffer is full
    SSPDR = (address << 8) | w_data; // data for device 1
    while(LED_BUSY){}    // wait if transfering data
    SSEL_HI;        // SSEL1 high, latch data to devices
  } else if (device == 2){  
    while(!LED_TNF){}    // wait if transmit buffer is full
    SSEL_LO;        // SSEL1 low
    SSPDR = (address << 8) | w_data; // data for device 2
    while(!LED_TNF){}    // wait if transmit buffer is full
    SSPDR = NO_OP;           // dummy data for device 1
    while(LED_BUSY){}    // wait if transfering data
    SSEL_HI;        // SSEL1 high
  }
}

void ui_led_pwm(unsigned int ui_led_num, unsigned int color, unsigned int pwm)
{
  //PWM level should be between 3 and 254
  unsigned int dev, addr, tmp;
  
  if (pwm < 3){
    pwm = 1;
  } else if (pwm > 254){
    pwm = 0;
  }
  
  tmp = (ui_led_num * 3) + color;
  dev = (tmp / 9) + 1; //leds 0-2 are on device 1, and leds 3-5 are on device 2
  addr = tmp % 9;  

  ui_led_register_write(dev, addr, pwm);
}

void ui_led_rgb(unsigned int ui_led_num, unsigned int red_level, unsigned int green_level, unsigned int blue_level)
{
  //PWM level should be between 3 and 254
  ui_led_pwm(ui_led_num, R, red_level);
  ui_led_pwm(ui_led_num, G, green_level);
  ui_led_pwm(ui_led_num, B, blue_level);
}