+#define cfg_write(mode, color) do { \
+ eeprom_write(CFG_MODE_ADDR, (mode)); \
+ eeprom_write(CFG_COLOR_ADDR, (color)); \
+ } while (0)
+
+#define cfg_read(mode, color) do { \
+ unsigned char tmp; \
+ tmp = eeprom_read(CFG_MODE_ADDR); \
+ mode = (tmp < MODE_COUNT) ? tmp : MODE_SOLID; \
+ tmp = eeprom_read(CFG_COLOR_ADDR); \
+ color = (tmp < COLOR_COUNT) ? tmp : 0; \
+ } while (0)
+
+enum {
+ /* Operating modes */
+ MODE_SOLID = 0, /* Cycle through colors[][] before next mode */
+ //MODE_CANDLE,
+ MODE_CYCLE, /* Auto cycle through colors */
+ MODE_PARTY, /* Random yet fast incolor and fade */
+ MODE_COUNT,
+
+ /* Indexes in colors[][] for LEDs */
+ LED_RED = 0,
+ LED_GRN,
+ LED_BLU,
+ LED_WHT,
+ LED_COUNT,
+
+ HELD_TMR_PERIODS = 1, /* Held timer fires every 32.768 msec */
+ HELD_PERIODS = 16, /* Held this long before held events fire */
+ COLOR_WHITE = 0, /* Color index for white */
+ COLOR_COUNT = 11,
+ BRIGHT_TOP = 100, /* Bright ramps up to top ... */
+ BRIGHT_BOTTOM = -5, /* ... then down to bottom */
+ BRIGHT_MAX = 85, /* Bright values are constrained for computations */
+ BRIGHT_MIN = 1, /* ... by min and max. */
+ BRIGHT_INIT = 42, /* later, get from eeprom */
+ STD_FADE = 16, /* Fade time in 32.768 ms units */
+ STD_INCOLOR = 29491, /* Time in color when MODE_CYCLE, in 32.768 ms units */
+ PARTY_MIN = 8, /* Min party fade and incolor units */
+ PARTY_RANGE = 8, /* Party fade/incolor range mask for rand() */
+ /* ... see start_fade() */
+ CFG_MODE_ADDR = 0, /* EEPROM address of mode variable */
+ CFG_COLOR_ADDR, /* EEPROM address of color variable */
+ CFG_DELAY = 92, /* 3 seconds in 32.768 msec units */
+};
+
+typedef struct {
+ int value;
+ int increment;
+ signed char remainder;
+} led_t;
+
+/* Available colors, 6 bits per color (no values above 0x3f) */
+const unsigned char colors[COLOR_COUNT][LED_COUNT] = {
+ { 0x28, 0x00, 0x00, 0x00 }, /* red */
+ { 0x30, 0x20, 0x00, 0x00 }, /* orange */
+ { 0x2c, 0x2c, 0x00, 0x00 }, /* yellow */
+ { 0x20, 0x2c, 0x00, 0x00 }, /* yellow-green */
+ { 0x00, 0x30, 0x00, 0x00 }, /* green */
+ { 0x00, 0x30, 0x18, 0x00 }, /* green-cyan */
+ { 0x00, 0x30, 0x28, 0x00 }, /* cyan */
+ { 0x00, 0x18, 0x30, 0x00 }, /* cyan-blue */
+ { 0x00, 0x00, 0x30, 0x00 }, /* blue */
+ { 0x1c, 0x00, 0x30, 0x00 }, /* magenta */
+ { 0x3f, 0x3f, 0x3f, 0x3f }, /* white */
+};
+
+unsigned char mode = MODE_SOLID;
+unsigned char color = COLOR_WHITE;
+led_t red;
+led_t grn;
+led_t blu;
+led_t wht;
+bit on;
+int fade_steps;
+signed char bright = BRIGHT_INIT;
+bit bright_up;
+signed char pbHeldCount;
+
+/* Combine LED color value and brightness level to generate an RGB value.
+ * bright will be BRIGHT_MIN...BRIGHT_MAX
+ *
+ * @param value 0...1023 (6 bit color, left shifted 4 bits, for 10 bits)
+ * @param b brightness value BRIGHT_MIN...BRIGHT_MAX
+ * @return An RGB drive value, 0...255
+ */
+unsigned char led_get(int value, signed char b)
+{
+ return (unsigned long)value * b / 4 / BRIGHT_MAX;
+}
+
+/* Set the LEDs using color values and current brightness. */
+void leds_set()
+{
+ signed char b;
+
+ if (bright > BRIGHT_MAX)
+ b = BRIGHT_MAX;
+ else if (bright < BRIGHT_MIN)
+ b = BRIGHT_MIN;
+ else
+ b = bright;
+ rgb_set(led_get((red).value, b), led_get((grn).value, b),
+ led_get((blu).value, b), led_get((wht).value, b));
+}
+
+void start_fade()
+{
+ /* RGB PWM values are 8 bits. Color values are 12 bits. See led_get()
+ * for the conversion of color values and brightness to RGB values.
+ */
+ int newr, newg, newb, neww;
+
+ /* Select the destination color and fade-to time depending upon mode. */
+ fade_steps = STD_FADE;
+ if (mode == MODE_PARTY) {
+ color = rand() % COLOR_COUNT;
+ fade_steps = PARTY_MIN + (rand() % PARTY_RANGE);
+ } else if (mode == MODE_CYCLE) {
+ if (++color == COLOR_COUNT)
+ color = 0;
+ }
+
+ /* Retrieve the destination color */
+ newr = colors[color][LED_RED] << 4;
+ newg = colors[color][LED_GRN] << 4;
+ newb = colors[color][LED_BLU] << 4;
+ neww = colors[color][LED_WHT] << 4;
+
+ /* Compute increment per fade step, and remainder, for each led */
+ red.increment = (newr - red.value) / fade_steps;
+ red.remainder = newr - (red.value + red.increment * fade_steps);
+ grn.increment = (newg - grn.value) / fade_steps;
+ grn.remainder = newg - (grn.value + grn.increment * fade_steps);
+ blu.increment = (newb - blu.value) / fade_steps;
+ blu.remainder = newb - (blu.value + blu.increment * fade_steps);
+ wht.increment = (neww - wht.value) / fade_steps;
+ wht.remainder = neww - (wht.value + wht.increment * fade_steps);
+
+ /* Start the fade timer */
+ tmr_stop(TMR_INCOLOR);
+ tmr_startPeriodic(TMR_FADE, 1); /* 32.768 msec */
+}
+
+void turnOn()