qmk_firmware/keyboards/clueboard/card/card.c

#include "card.h"

#define BL_RED OCR1B
#define BL_GREEN OCR1A
#define BL_BLUE OCR1C

void backlight_init_ports(void)
{
	// Set B5, B6, and B7 as output
	DDRB |= (1<<7)|(1<<6)|(1<<5);

	// Setup PWM
	ICR1 = 0xFFFF;
	TCCR1A = 0b10101010;
	TCCR1B = 0b00011001;

	BL_RED = 0xFFFF;
	BL_GREEN = 0xFFFF;
	BL_BLUE = 0xFFFF;
}

void backlight_set(uint8_t level)
{
	// Set the RGB color
	switch (level)
	{
	case 0:
		// Off
		BL_RED = 0xFFFF;
		BL_GREEN = 0xFFFF;
		BL_BLUE = 0xFFFF;
		break;
	case 1:
		// Red
		BL_RED = 0x0000;
		BL_GREEN = 0xFFFF;
		BL_BLUE = 0xFFFF;
		break;
	case 2:
		// Green
		BL_RED = 0xFFFF;
		BL_GREEN = 0x0000;
		BL_BLUE = 0xFFFF;
		break;
	case 3:
		// Blue
		BL_RED = 0xFFFF;
		BL_GREEN = 0xFFFF;
		BL_BLUE = 0x0000;
		break;
	case 4:
		// Magenta
		BL_RED = 0x4000;
		BL_GREEN = 0x4000;
		BL_BLUE = 0x4000;
		break;
	case 5:
		// Purple
		BL_RED = 0x0000;
		BL_GREEN = 0xFFFF;
		BL_BLUE = 0x0000;
		break;
	case 6:
		// Yellow
		BL_RED = 0x0000;
		BL_GREEN = 0x0000;
		BL_BLUE = 0xFFFF;
		break;
	default:
		xprintf("Unknown level: %d\n", level);
	}
}