From f8e1150ba52fb3128d452e68ae2d8dda97a53ff1 Mon Sep 17 00:00:00 2001
From: Selene ToyKeeper
Date: Fri, 14 Apr 2023 18:01:03 -0600
Subject: LT1S Pro: added dynamic PWM (much better low modes!)

---
 hwdef-Sofirn_LT1S-Pro.c | 114 ++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 100 insertions(+), 14 deletions(-)

(limited to 'hwdef-Sofirn_LT1S-Pro.c')

diff --git a/hwdef-Sofirn_LT1S-Pro.c b/hwdef-Sofirn_LT1S-Pro.c
index 3c31c96..61d2157 100644
--- a/hwdef-Sofirn_LT1S-Pro.c
+++ b/hwdef-Sofirn_LT1S-Pro.c
@@ -5,22 +5,105 @@
 #pragma once
 
 
-// "auto tint" channel mode
-void set_level_auto_3ch_blend(uint8_t level) {
-    BLEND_PWM_DATATYPE vpwm;
-
+// single set of LEDs with 1 power channel and dynamic PWM
+void set_level_1ch_dyn(uint8_t level) {
     if (level == 0) {
-        vpwm  = 0;
+        RED_PWM_LVL  = 0;
+        PWM_CNT      = 0;  // reset phase
     } else {
         level --;  // PWM array index = level - 1
-        vpwm  = PWM_GET(blend_pwm_levels, level);
+        RED_PWM_LVL  = PWM_GET(pwm1_levels, level);
+        // pulse frequency modulation, a.k.a. dynamic PWM
+        PWM_TOP = PWM_GET(pwm_tops, level);
+        // force reset phase when turning on from zero
+        // (because otherwise the initial response is inconsistent)
+        if (! actual_level) PWM_CNT = 0;
+    }
+}
+
+
+// warm + cool blend w/ middle sag correction and dynamic PWM
+void set_level_2ch_dyn_blend(uint8_t level) {
+    #ifndef TINT_RAMPING_CORRECTION
+    #define TINT_RAMPING_CORRECTION 26  // 140% brightness at middle tint
+    #endif
+
+    if (level == 0) {
+        WARM_PWM_LVL = 0;
+        COOL_PWM_LVL = 0;
+        PWM_CNT      = 0;  // reset phase
+        return;
+    }
+
+    level --;  // PWM array index = level - 1
+    PWM_DATATYPE brightness = PWM_GET(pwm1_levels, level);
+    uint16_t top = PWM_GET(pwm_tops, level);
+
+    // calculate actual PWM levels based on a single-channel ramp
+    // and a global tint value
+    uint16_t warm_PWM, cool_PWM;
+    uint8_t mytint = channel_mode_args[channel_mode];
+
+    PWM_DATATYPE2 base_PWM = brightness;
+    #if defined(TINT_RAMPING_CORRECTION) && (TINT_RAMPING_CORRECTION > 0)
+        // middle tints sag, so correct for that effect
+        // by adding extra power which peaks at the middle tint
+        // (correction is only necessary when PWM is fast)
+        if (level > HALFSPEED_LEVEL) {
+            base_PWM = brightness
+                     + ((((PWM_DATATYPE2)brightness) * TINT_RAMPING_CORRECTION / 64)
+                        * triangle_wave(mytint) / 255);
+        }
+        // fade the triangle wave out when above 100% power,
+        // so it won't go over 200%
+        if (brightness > top) {
+            base_PWM -= 2 * (
+                             ((brightness - top) * TINT_RAMPING_CORRECTION / 64)
+                             * triangle_wave(mytint) / 255
+                        );
+        }
+        // guarantee no more than 200% power
+        if (base_PWM > (top << 1)) { base_PWM = top << 1; }
+    #endif
+
+    cool_PWM = (((PWM_DATATYPE2)mytint * (PWM_DATATYPE2)base_PWM) + 127) / 255;
+    warm_PWM = base_PWM - cool_PWM;
+    // when running at > 100% power, spill extra over to other channel
+    if (cool_PWM > top) {
+        warm_PWM += (cool_PWM - top);
+        cool_PWM = top;
+    } else if (warm_PWM > top) {
+        cool_PWM += (warm_PWM - top);
+        warm_PWM = top;
+    }
+
+    WARM_PWM_LVL = warm_PWM;
+    COOL_PWM_LVL = cool_PWM;
+    PWM_TOP = top;
+    if (! actual_level) PWM_CNT = 0;  // reset phase
+}
+
+
+// "auto tint" channel mode with dynamic PWM
+void set_level_auto_3ch_dyn_blend(uint8_t level) {
+    if (level == 0) {
+        WARM_PWM_LVL = 0;
+        COOL_PWM_LVL = 0;
+        RED_PWM_LVL  = 0;
+        PWM_CNT      = 0;  // reset phase
+        return;
     }
 
+    level --;  // PWM array index = level - 1
+    PWM_DATATYPE vpwm = PWM_GET(pwm1_levels, level);
+    // pulse frequency modulation, a.k.a. dynamic PWM
+    uint16_t top = PWM_GET(pwm_tops, level);
+
     // tint goes from 0 (red) to 127 (warm white) to 255 (cool white)
     uint8_t mytint;
     mytint = 255 * (uint16_t)level / RAMP_SIZE;
 
-    BLEND_PWM_DATATYPE a, b, c;
+    PWM_DATATYPE a, b, c;
 
     // red is high at 0, low at 255
     a = (((PWM_DATATYPE2)(255 - mytint)
@@ -35,6 +118,8 @@ void set_level_auto_3ch_blend(uint8_t level) {
     RED_PWM_LVL  = a;
     WARM_PWM_LVL = b;
     COOL_PWM_LVL = c;
+    PWM_TOP = top;
+    if (! actual_level) PWM_CNT = 0;
 }
 
 
@@ -42,19 +127,19 @@ void set_level_auto_3ch_blend(uint8_t level) {
 void set_level_red_white_blend(uint8_t level) {
     // set the warm+cool white LEDs first
     channel_mode = CM_WHITE;
-    set_level_2ch_blend(level);
+    set_level_2ch_dyn_blend(level);
     channel_mode = CM_WHITE_RED;
 
-    BLEND_PWM_DATATYPE vpwm;
-
     // set the red LED as a ratio of the white output level
     if (level == 0) {
-        vpwm  = 0;
-    } else {
-        level --;  // PWM array index = level - 1
-        vpwm  = PWM_GET(blend_pwm_levels, level);
+        RED_PWM_LVL = 0;
+        PWM_CNT     = 0;  // reset phase
+        return;
     }
 
+    level --;  // PWM array index = level - 1
+    PWM_DATATYPE vpwm = PWM_GET(pwm1_levels, level);
+
     // 0 = no red
     // 255 = red at 100% of white channel PWM
     uint8_t ratio = channel_mode_args[channel_mode];
@@ -63,5 +148,6 @@ void set_level_red_white_blend(uint8_t level) {
     red_pwm = (((PWM_DATATYPE2)ratio * (PWM_DATATYPE2)vpwm) + 127) / 255;
 
     RED_PWM_LVL = red_pwm;
+    if (! actual_level) PWM_CNT = 0;  // reset phase
 }
 
-- 
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