From 4a2f3d87c5bd8e9ffc9369dccfdb8940ee3656ea Mon Sep 17 00:00:00 2001
From: to-scho <tobias.scholand@gmail.com>
Date: Sun, 29 Mar 2020 17:05:52 +0200
Subject: [PATCH] Enhanced counter debouncing

New commands CounterDebounceLow and CounterDebounceHigh to allow individual debounce times for low and high pulse widths to discard non valid falling edges. These are checked before legacy CounterDebounce checks distance between to valid falling edges.
Useful to have robust counter results when using e.g. an TCRT5000 optical sensor to count electromechanical "Ferraris" electricity meters.
---
 tasmota/settings.h          |  4 ++-
 tasmota/xsns_01_counter.ino | 59 ++++++++++++++++++++++++++++++++++---
 2 files changed, 58 insertions(+), 5 deletions(-)

diff --git a/tasmota/settings.h b/tasmota/settings.h
index fa98a8ecf..7bbb0e5de 100644
--- a/tasmota/settings.h
+++ b/tasmota/settings.h
@@ -470,8 +470,10 @@ struct SYSCFG {
   uint8_t       bri_preset_high;           // F07
   int8_t        hum_comp;                  // F08
 
-  uint8_t       free_f09[179];             // F09
+  uint8_t       free_f09[175];             // F09
 
+  uint16_t      pulse_counter_debounce_low;  // FB8
+  uint16_t      pulse_counter_debounce_high; // FBA
   uint32_t      keeloq_master_msb;         // FBC
   uint32_t      keeloq_master_lsb;         // FC0
   uint32_t      keeloq_serial;             // FC4
diff --git a/tasmota/xsns_01_counter.ino b/tasmota/xsns_01_counter.ino
index 095693771..663d9413a 100644
--- a/tasmota/xsns_01_counter.ino
+++ b/tasmota/xsns_01_counter.ino
@@ -27,16 +27,20 @@
 #define D_PRFX_COUNTER "Counter"
 #define D_CMND_COUNTERTYPE "Type"
 #define D_CMND_COUNTERDEBOUNCE "Debounce"
+#define D_CMND_COUNTERDEBOUNCELOW "DebounceLow"
+#define D_CMND_COUNTERDEBOUNCEHIGH "DebounceHigh"
 
 const char kCounterCommands[] PROGMEM = D_PRFX_COUNTER "|"  // Prefix
-  "|" D_CMND_COUNTERTYPE "|" D_CMND_COUNTERDEBOUNCE ;
+  "|" D_CMND_COUNTERTYPE "|" D_CMND_COUNTERDEBOUNCE  "|" D_CMND_COUNTERDEBOUNCELOW "|" D_CMND_COUNTERDEBOUNCEHIGH ;
 
 void (* const CounterCommand[])(void) PROGMEM = {
-  &CmndCounter, &CmndCounterType, &CmndCounterDebounce };
+  &CmndCounter, &CmndCounterType, &CmndCounterDebounce, &CmndCounterDebounceLow, &CmndCounterDebounceHigh };
 
 struct COUNTER {
   uint32_t timer[MAX_COUNTERS];  // Last counter time in micro seconds
+  uint32_t timer_low_high[MAX_COUNTERS];  // Last low/high counter time in micro seconds
   uint8_t no_pullup = 0;         // Counter input pullup flag (1 = No pullup)
+  uint8_t pin_state = 0;         // LSB0..3 Last state of counter pin; LSB7==0 IRQ is FALLING, LSB7==1 IRQ is CHANGE
   bool any_counter = false;
 } Counter;
 
@@ -51,7 +55,30 @@ void CounterUpdate4(void) ICACHE_RAM_ATTR;
 void CounterUpdate(uint8_t index)
 {
   uint32_t time = micros();
-  uint32_t debounce_time = time - Counter.timer[index];
+  uint32_t debounce_time;
+
+  if (Counter.pin_state) {
+    // handle low and high debounce times when configured
+    if (digitalRead(pin[GPIO_CNTR1 +index]) == bitRead(Counter.pin_state, index)) {
+      // new pin state to be ignored because debounce time was not met during last IRQ
+      return;
+    }
+    debounce_time = time - Counter.timer_low_high[index];
+    if bitRead(Counter.pin_state, index) {
+      // last valid pin state was high, current pin state is low
+      if (debounce_time <= Settings.pulse_counter_debounce_high * 1000) return;
+    } else {
+      // last valid pin state was low, current pin state is high
+      if (debounce_time <= Settings.pulse_counter_debounce_low * 1000) return;
+    }
+    // passed debounce check, save pin state and timing
+    Counter.timer_low_high[index] = time;
+    Counter.pin_state ^= (1<<index);
+    // do not count on rising edge
+    if bitRead(Counter.pin_state, index) return;
+  }
+
+  debounce_time = time - Counter.timer[index];
   if (debounce_time > Settings.pulse_counter_debounce * 1000) {
     Counter.timer[index] = time;
     if (bitRead(Settings.pulse_counter_type, index)) {
@@ -103,7 +130,13 @@ void CounterInit(void)
     if (pin[GPIO_CNTR1 +i] < 99) {
       Counter.any_counter = true;
       pinMode(pin[GPIO_CNTR1 +i], bitRead(Counter.no_pullup, i) ? INPUT : INPUT_PULLUP);
-      attachInterrupt(pin[GPIO_CNTR1 +i], counter_callbacks[i], FALLING);
+      if ((0 == Settings.pulse_counter_debounce_low) && (0 == Settings.pulse_counter_debounce_high)) {
+        Counter.pin_state = 0;
+        attachInterrupt(pin[GPIO_CNTR1 +i], counter_callbacks[i], FALLING);
+      } else {
+        Counter.pin_state = 0x8f;
+        attachInterrupt(pin[GPIO_CNTR1 +i], counter_callbacks[i], CHANGE);
+      }
     }
   }
 }
@@ -213,6 +246,24 @@ void CmndCounterDebounce(void)
   ResponseCmndNumber(Settings.pulse_counter_debounce);
 }
 
+void CmndCounterDebounceLow(void)
+{
+  if ((XdrvMailbox.payload >= 0) && (XdrvMailbox.payload < 32001)) {
+    Settings.pulse_counter_debounce_low = XdrvMailbox.payload;
+    CounterInit();
+  }
+  ResponseCmndNumber(Settings.pulse_counter_debounce_low);
+}
+
+void CmndCounterDebounceHigh(void)
+{
+  if ((XdrvMailbox.payload >= 0) && (XdrvMailbox.payload < 32001)) {
+    Settings.pulse_counter_debounce_high = XdrvMailbox.payload;
+    CounterInit();
+  }
+  ResponseCmndNumber(Settings.pulse_counter_debounce_high);
+}
+
 /*********************************************************************************************\
  * Interface
 \*********************************************************************************************/