CIE 1931 for the LCD backlight

pull/1217/head
Fred Sundvik 8 years ago
parent f113f95440
commit 951b6f33a0

@ -70,10 +70,33 @@ void lcd_backlight_hal_init(void) {
RGB_PORT->PCR[BLUE_PIN] = RGB_MODE;
}
static uint16_t cie_lightness(uint16_t v) {
// The CIE 1931 formula for lightness
// Y = luminance (output) 0-1
// L = lightness input 0 - 100
// Y = (L* / 902.3) if L* <= 8
// Y = ((L* + 16) / 116)^3 if L* > 8
float l = 100.0f * (v / 65535.0f);
float y = 0.0f;
if (l <= 8.0f) {
y = l / 902.3;
}
else {
y = ((l + 16.0f) / 116.0f);
y = y * y * y;
if (y > 1.0f) {
y = 1.0f;
}
}
return y * 65535.0f;
}
void lcd_backlight_hal_color(uint16_t r, uint16_t g, uint16_t b) {
CHANNEL_RED.CnV = r;
CHANNEL_GREEN.CnV = g;
CHANNEL_BLUE.CnV = b;
CHANNEL_RED.CnV = cie_lightness(r);
CHANNEL_GREEN.CnV = cie_lightness(g);
CHANNEL_BLUE.CnV = cie_lightness(b);
}
__attribute__ ((weak))

@ -70,8 +70,8 @@ static const uint8_t image_data_lcd_logo[512] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
static const uint32_t logo_background_color = LCD_COLOR(0x00, 0x00, 0x80);
static const uint32_t initial_color = LCD_COLOR(0, 0, 0xFF);
static const uint32_t logo_background_color = LCD_COLOR(0x00, 0x00, 0xFF);
static const uint32_t initial_color = LCD_COLOR(0, 0, 0);
bool display_logo(keyframe_animation_t* animation, visualizer_state_t* state) {
(void)state;
@ -155,7 +155,7 @@ static keyframe_animation_t resume_animation = {
void initialize_user_visualizer(visualizer_state_t* state) {
// The brightness will be dynamically adjustable in the future
// But for now, change it here.
lcd_backlight_brightness(0x50);
lcd_backlight_brightness(130);
state->current_lcd_color = initial_color;
state->target_lcd_color = logo_background_color;
start_keyframe_animation(&startup_animation);

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