backlight.h

// backlight.h — Display illumination control (PB2 active-low driver).
//
// PB2 is DC-driven, not wired to any hardware PWM channel (Timer1 is
// reserved exclusively for audio, and Timer2's PWM pins are PB3/PD3, not
// PB2). Brightness control below is therefore a small software PWM,
// serviced from the main loop -- non-blocking, no hardware timer needed.

#ifndef BACKLIGHT_H
#define BACKLIGHT_H

#include <stdint.h>

void backlightInit(void);

// 0-100 (%). Takes effect gradually as backlightUpdate() services the
// software PWM cycle; doesn't switch the pin immediately.
void backlightSetBrightness(uint8_t percent);

// Call once per main loop iteration with the current systemGetTimeMs().
void backlightUpdate(uint32_t nowMs);

#endif // BACKLIGHT_H