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// Noctigon DM11 (boost driver) PWM helper functions
// Copyright (C) 2023 Selene ToyKeeper
// SPDX-License-Identifier: GPL-3.0-or-later
#pragma once
#include "chan-rgbaux.c"
void set_level_zero();
void set_level_main(uint8_t level);
bool gradual_tick_main(uint8_t gt);
Channel channels[] = {
{ // channel 1 only
.set_level = set_level_main,
.gradual_tick = gradual_tick_main
},
RGB_AUX_CHANNELS
};
void set_level_zero() {
// disable timer overflow interrupt
// (helps improve button press handling from Off state)
DSM_INTCTRL &= ~DSM_OVF_bm;
// turn off all LEDs
ch1_dsm_lvl = 0;
CH1_PWM = 0;
PWM_CNT = 0; // reset phase
CH1_ENABLE_PORT &= ~(1 << CH1_ENABLE_PIN ); // disable opamp
CH1_ENABLE_PORT2 &= ~(1 << CH1_ENABLE_PIN2); // disable PMIC
}
// single set of LEDs with single power channel, boost
void set_level_main(uint8_t level) {
PWM_DATATYPE ch1 = PWM_GET(pwm1_levels, level);
// set delta-sigma soft levels
ch1_dsm_lvl = ch1;
// set hardware PWM levels and init dsm loop
CH1_PWM = ch1_pwm = ch1 >> 7;
// enable timer overflow interrupt so DSM can work
DSM_INTCTRL |= DSM_OVF_bm;
// force reset phase when turning on from zero
// (because otherwise the initial response is inconsistent)
if (! actual_level) PWM_CNT = 0;
CH1_ENABLE_PORT |= (1 << CH1_ENABLE_PIN ); // enable opamp
CH1_ENABLE_PORT2 |= (1 << CH1_ENABLE_PIN2); // enable PMIC
}
// delta-sigma modulation of PWM outputs
// happens on each Timer overflow (every 512 cpu clock cycles)
// uses 8-bit pwm w/ 7-bit dsm (0b 0PPP PPPP PDDD DDDD)
ISR(DSM_vect) {
// set new hardware values first,
// for best timing (reduce effect of interrupt jitter)
CH1_PWM = ch1_pwm;
// calculate next values, now that timing matters less
// accumulate error
ch1_dsm += (ch1_dsm_lvl & 0x007f);
// next PWM = base PWM value + carry bit
ch1_pwm = (ch1_dsm_lvl >> 7) + (ch1_dsm > 0x7f);
// clear carry bit
ch1_dsm &= 0x7f;
}
bool gradual_tick_main(uint8_t gt) {
PWM_DATATYPE ch1 = PWM_GET(pwm1_levels, gt);
// adjust multiple times based on current brightness
// (so it adjusts faster/coarser when bright, slower/finer when dim)
// higher shift = slower/finer adjustments
const uint8_t shift = 9; // ((255 << 7) >> 9) = 63 max
uint8_t steps;
steps = ch1_dsm_lvl >> shift;
for (uint8_t i=0; i<=steps; i++)
GRADUAL_ADJUST_SIMPLE(ch1, ch1_dsm_lvl);
if ((ch1 == ch1_dsm_lvl)
) {
return true; // done
}
return false; // not done yet
}
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