From a810456ef153218837effca6833dcd59e8fef96f Mon Sep 17 00:00:00 2001
From: "Adrian A. Baumann" <ade@adebaumann.com>
Date: Mon, 29 Jun 2026 01:54:57 +0200
Subject: [PATCH] Discard odd-position '1' bursts: filter wind-up spurious
 pulse

---
 src/main.cpp | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index 52b7807..91abbf0 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -23,7 +23,7 @@
 // ---------------------------------------------------------------------------
 
 #define DIAL_PIN          4     // GPIO connected to the pulse contact (to GND)
-#define PULSE_DEBOUNCE_MS 15    // ignore edges faster than this
+#define PULSE_DEBOUNCE_MS 100    // ignore edges faster than this
 #define INTER_PULSE_MS    350   // silence longer than this = digit complete
 #define INTER_DIGIT_MS    2500  // silence longer than this = number complete, publish
 
@@ -58,6 +58,7 @@ static volatile int           dialPulses    = 0;
 static volatile unsigned long dialLastPulse = 0;  // millis() of last counted pulse
 static String                 dialNumber    = "";
 static unsigned long          dialLastDigit = 0;  // millis() of last completed digit
+static int                    dialRawCount  = 0;  // raw digit count since last publish (odd positions = wind-up spurious)
 
 static void IRAM_ATTR onDialPulse() {
   unsigned long now = millis();
@@ -278,11 +279,17 @@ static void dialLoop() {
     interrupts();
     lastLoggedPulses = 0;
 
+    dialRawCount++;
     // 10 pulses = digit '0'; 1–9 pulses = digits '1'–'9'
     char digit = '0' + (pulses >= 10 ? 0 : pulses);
-    dialNumber += digit;
-    dialLastDigit = now;
-    Serial.printf("[DIAL] burst end pulses=%d -> digit='%c' number_so_far=%s\n", pulses, digit, dialNumber.c_str());
+    bool spurious = (dialRawCount % 2 == 1) && (digit == '1');
+    if (spurious) {
+      Serial.printf("[DIAL] burst end pulses=%d -> digit='%c' (wind-up spurious, discarded)\n", pulses, digit);
+    } else {
+      dialNumber += digit;
+      dialLastDigit = now;
+      Serial.printf("[DIAL] burst end pulses=%d -> digit='%c' number_so_far=%s\n", pulses, digit, dialNumber.c_str());
+    }
   }
 
   // Number complete when no further digits arrive within the timeout
@@ -290,6 +297,15 @@ static void dialLoop() {
     Serial.printf("[DIAL] number complete=%s\n", dialNumber.c_str());
     mqttPublishDialed(dialNumber);
     dialNumber = "";
+    dialRawCount = 0;
+  }
+
+  // If the sequence stalled with no accepted digit (e.g. user wound up then
+  // stopped), reset the count so the next wind-up is treated as position 1.
+  if (dialRawCount > 0 && dialNumber.length() == 0 && pulses == 0
+      && (now - lastPulse) >= INTER_DIGIT_MS) {
+    Serial.println("[DIAL] idle reset");
+    dialRawCount = 0;
   }
 }