From 3f6a9fe82d892a1fca198169a7d3ed7bba58f902 Mon Sep 17 00:00:00 2001
From: Selene ToyKeeper
Date: Wed, 8 Dec 2021 15:31:00 -0700
Subject: added a compile option for USE_LOWPASS_WHILE_ASLEEP, but it doesn't
 actually fix the issue I was hoping it'd fix, so it's disabled by default
 (when the battery is right on a threshold between colors for aux LED
 "voltage" mode, it can bounce between colors until the cell isn't on the
 boundary any more... but a simple lowpass doesn't really help) (but I also
 didn't want to throw out the code, in case it's useful later as a reference
 for a more effective solution)

---
 spaghetti-monster/anduril/cfg-ff-rot66.h           |  5 +++--
 .../anduril/cfg-mateminco-mf01-mini.h              |  4 +++-
 spaghetti-monster/anduril/config-default.h         |  4 ++++
 spaghetti-monster/fsm-adc.c                        | 22 ++++++++++++++++++++--
 spaghetti-monster/fsm-standby.c                    |  2 ++
 5 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/spaghetti-monster/anduril/cfg-ff-rot66.h b/spaghetti-monster/anduril/cfg-ff-rot66.h
index 03b74db..e2d5ff7 100644
--- a/spaghetti-monster/anduril/cfg-ff-rot66.h
+++ b/spaghetti-monster/anduril/cfg-ff-rot66.h
@@ -49,5 +49,6 @@
 //#undef USE_TACTICAL_STROBE_MODE
 
 // reduce size a bit
-#define NO_LOWPASS_WHILE_ASLEEP
-
+#ifdef USE_LOWPASS_WHILE_ASLEEP
+#undef USE_LOWPASS_WHILE_ASLEEP
+#endif
diff --git a/spaghetti-monster/anduril/cfg-mateminco-mf01-mini.h b/spaghetti-monster/anduril/cfg-mateminco-mf01-mini.h
index 09b684f..b5c3b12 100644
--- a/spaghetti-monster/anduril/cfg-mateminco-mf01-mini.h
+++ b/spaghetti-monster/anduril/cfg-mateminco-mf01-mini.h
@@ -59,5 +59,7 @@
 //#undef USE_2C_STYLE_CONFIG
 
 // reduce size a bit
-#define NO_LOWPASS_WHILE_ASLEEP
+#ifdef USE_LOWPASS_WHILE_ASLEEP
+#undef USE_LOWPASS_WHILE_ASLEEP
+#endif
 
diff --git a/spaghetti-monster/anduril/config-default.h b/spaghetti-monster/anduril/config-default.h
index 406e98b..77b5c6b 100644
--- a/spaghetti-monster/anduril/config-default.h
+++ b/spaghetti-monster/anduril/config-default.h
@@ -189,5 +189,9 @@
 // (defined here so config files can override it)
 #define USE_DYNAMIC_UNDERCLOCKING
 
+// if the aux LEDs oscillate between "full battery" and "empty battery"
+// while in "voltage" mode, enable this to reduce the amplitude of
+// those oscillations
+//#define USE_LOWPASS_WHILE_ASLEEP
 
 #endif
diff --git a/spaghetti-monster/fsm-adc.c b/spaghetti-monster/fsm-adc.c
index 975d12e..c5401ea 100644
--- a/spaghetti-monster/fsm-adc.c
+++ b/spaghetti-monster/fsm-adc.c
@@ -306,10 +306,28 @@ static inline void ADC_voltage_handler() {
     uint16_t measurement;
 
     // latest ADC value
-    if (adc_reset) {  // while asleep, or just after waking, don't lowpass
+    if (adc_reset) {  // just after waking, don't lowpass
         measurement = adc_raw[0];
-        adc_smooth[0] = measurement;  // no lowpass while asleep
+        adc_smooth[0] = measurement;  // no lowpass, just use the latest value
     }
+    #ifdef USE_LOWPASS_WHILE_ASLEEP
+    else if (go_to_standby) {  // weaker lowpass while asleep
+        // occasionally the aux LED color can oscillate during standby,
+        // while using "voltage" mode ... so try to reduce the oscillation
+        uint16_t m = adc_raw[0];
+        uint16_t v = adc_smooth[0];
+        #if 0
+        // fixed-rate lowpass, slow, more stable but takes longer to settle
+        if (m < v) { v -= 64; }
+        if (m > v) { v += 64; }
+        #else
+        // weighted lowpass, faster but less stable
+        v = (m>>1) + (v>>1);
+        #endif
+        adc_smooth[0] = v;
+        measurement = v;
+    }
+    #endif
     else measurement = adc_smooth[0];
 
     // values stair-step between intervals of 64, with random variations
diff --git a/spaghetti-monster/fsm-standby.c b/spaghetti-monster/fsm-standby.c
index c450bca..0ae6a2f 100644
--- a/spaghetti-monster/fsm-standby.c
+++ b/spaghetti-monster/fsm-standby.c
@@ -73,7 +73,9 @@ void sleep_until_eswitch_pressed()
             go_to_standby = 0;
         }
         if (irq_adc) {  // ADC done measuring
+            #ifndef USE_LOWPASS_WHILE_ASLEEP
             adc_reset = 1;  // don't lowpass while asleep
+            #endif
             adc_deferred_enable = 1;
             adc_deferred();
             //ADC_off();  // takes care of itself
-- 
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