diff --git a/quantum/backlight/backlight_avr.c b/quantum/backlight/backlight_avr.c index f3a0252270..474e0a86f5 100644 --- a/quantum/backlight/backlight_avr.c +++ b/quantum/backlight/backlight_avr.c @@ -405,14 +405,18 @@ ISR(TIMERx_OVF_vect) uint16_t interval = (uint16_t)get_breathing_period() * breathing_ISR_frequency / BREATHING_STEPS; // resetting after one period to prevent ugly reset at overflow. breathing_counter = (breathing_counter + 1) % (get_breathing_period() * breathing_ISR_frequency); - uint8_t index = breathing_counter / interval % BREATHING_STEPS; + uint8_t index = breathing_counter / interval; + // limit index to max step value + if (index >= BREATHING_STEPS) { + index = BREATHING_STEPS - 1; + } if (((breathing_halt == BREATHING_HALT_ON) && (index == BREATHING_STEPS / 2)) || ((breathing_halt == BREATHING_HALT_OFF) && (index == BREATHING_STEPS - 1))) { breathing_interrupt_disable(); } // Set PWM to a brightnessvalue scaled to the configured resolution - set_pwm(cie_lightness(rescale_limit_val(scale_backlight((uint16_t)pgm_read_byte(&breathing_table[index]) * ICRx / 255)))); + set_pwm(cie_lightness(rescale_limit_val(scale_backlight((uint32_t)pgm_read_byte(&breathing_table[index]) * ICRx / 255)))); } #endif // BACKLIGHT_BREATHING