From 5243b17a1a49de6b09871340260a809d2c64fb93 Mon Sep 17 00:00:00 2001
From: Theo Arends <11044339+arendst@users.noreply.github.com>
Date: Wed, 3 Nov 2021 11:58:05 +0100
Subject: [PATCH] Add 1 second heartbeat GPIO

---
 CHANGELOG.md                | 1 +
 RELEASENOTES.md             | 1 +
 tasmota/language/af_AF.h    | 1 +
 tasmota/language/bg_BG.h    | 1 +
 tasmota/language/cs_CZ.h    | 1 +
 tasmota/language/de_DE.h    | 1 +
 tasmota/language/el_GR.h    | 1 +
 tasmota/language/en_GB.h    | 1 +
 tasmota/language/es_ES.h    | 1 +
 tasmota/language/fr_FR.h    | 1 +
 tasmota/language/fy_NL.h    | 1 +
 tasmota/language/he_HE.h    | 1 +
 tasmota/language/hu_HU.h    | 1 +
 tasmota/language/it_IT.h    | 1 +
 tasmota/language/ko_KO.h    | 1 +
 tasmota/language/nl_NL.h    | 1 +
 tasmota/language/pl_PL.h    | 1 +
 tasmota/language/pt_BR.h    | 1 +
 tasmota/language/pt_PT.h    | 1 +
 tasmota/language/ro_RO.h    | 1 +
 tasmota/language/ru_RU.h    | 1 +
 tasmota/language/sk_SK.h    | 1 +
 tasmota/language/sv_SE.h    | 1 +
 tasmota/language/tr_TR.h    | 1 +
 tasmota/language/uk_UA.h    | 1 +
 tasmota/language/vi_VN.h    | 1 +
 tasmota/language/zh_CN.h    | 1 +
 tasmota/language/zh_TW.h    | 1 +
 tasmota/support_rtc.ino     | 6 ++++++
 tasmota/support_tasmota.ino | 9 +++++++++
 tasmota/tasmota.h           | 2 ++
 tasmota/tasmota.ino         | 4 ++++
 tasmota/tasmota_template.h  | 6 +++++-
 33 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ff6a13515..4a85f404d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ All notable changes to this project will be documented in this file.
 ## [10.0.0.1]
 ### Added
 - Berry add module ``python_compat`` to be closer to Python syntax (#13428)
+- 1 second heartbeat GPIO
 
 ### Changed
 - File editor no-wrap (#13427)
diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index e1c2708a5..4c85900cd 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -102,6 +102,7 @@ The latter links can be used for OTA upgrades too like ``OtaUrl http://ota.tasmo
 
 ## Changelog v10.0.0.1
 ### Added
+- 1 second heartbeat GPIO
 - ESP32 Berry add module ``python_compat`` to be closer to Python syntax [#13428](https://github.com/arendst/Tasmota/issues/13428)
 
 ### Breaking Changed
diff --git a/tasmota/language/af_AF.h b/tasmota/language/af_AF.h
index 5c1a80e48..62ffd8920 100644
--- a/tasmota/language/af_AF.h
+++ b/tasmota/language/af_AF.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/bg_BG.h b/tasmota/language/bg_BG.h
index f74e03c24..4c8478ea0 100644
--- a/tasmota/language/bg_BG.h
+++ b/tasmota/language/bg_BG.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/cs_CZ.h b/tasmota/language/cs_CZ.h
index 17d163560..08e72f1ea 100644
--- a/tasmota/language/cs_CZ.h
+++ b/tasmota/language/cs_CZ.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/de_DE.h b/tasmota/language/de_DE.h
index 1e0f05225..eeed35a6c 100644
--- a/tasmota/language/de_DE.h
+++ b/tasmota/language/de_DE.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/el_GR.h b/tasmota/language/el_GR.h
index f40d5108c..df517a383 100644
--- a/tasmota/language/el_GR.h
+++ b/tasmota/language/el_GR.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/en_GB.h b/tasmota/language/en_GB.h
index 26e0d57d6..79eb011f1 100644
--- a/tasmota/language/en_GB.h
+++ b/tasmota/language/en_GB.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/es_ES.h b/tasmota/language/es_ES.h
index a12da16ec..6ef4fa653 100644
--- a/tasmota/language/es_ES.h
+++ b/tasmota/language/es_ES.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/fr_FR.h b/tasmota/language/fr_FR.h
index 205c73c4b..5dad0c998 100644
--- a/tasmota/language/fr_FR.h
+++ b/tasmota/language/fr_FR.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/fy_NL.h b/tasmota/language/fy_NL.h
index 77f0f7582..569a0a830 100644
--- a/tasmota/language/fy_NL.h
+++ b/tasmota/language/fy_NL.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/he_HE.h b/tasmota/language/he_HE.h
index 43464a51c..b77b75a23 100644
--- a/tasmota/language/he_HE.h
+++ b/tasmota/language/he_HE.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/hu_HU.h b/tasmota/language/hu_HU.h
index 04a22efa8..713979b48 100644
--- a/tasmota/language/hu_HU.h
+++ b/tasmota/language/hu_HU.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/it_IT.h b/tasmota/language/it_IT.h
index 7759f4710..21ec94bdd 100644
--- a/tasmota/language/it_IT.h
+++ b/tasmota/language/it_IT.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX               "HRG15 - RX"
 #define D_SENSOR_HRG15_TX               "HRG15 - TX"
 #define D_SENSOR_VINDRIKTNING_RX        "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE                     "A"
diff --git a/tasmota/language/ko_KO.h b/tasmota/language/ko_KO.h
index 444e36c34..a4ce5eae0 100644
--- a/tasmota/language/ko_KO.h
+++ b/tasmota/language/ko_KO.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/nl_NL.h b/tasmota/language/nl_NL.h
index af90f2c06..7076b545f 100644
--- a/tasmota/language/nl_NL.h
+++ b/tasmota/language/nl_NL.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/pl_PL.h b/tasmota/language/pl_PL.h
index 8b9f119c2..52802b75c 100644
--- a/tasmota/language/pl_PL.h
+++ b/tasmota/language/pl_PL.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/pt_BR.h b/tasmota/language/pt_BR.h
index c1b937a4f..4b59fce59 100644
--- a/tasmota/language/pt_BR.h
+++ b/tasmota/language/pt_BR.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/pt_PT.h b/tasmota/language/pt_PT.h
index 3bd0d530c..a5bdc4974 100644
--- a/tasmota/language/pt_PT.h
+++ b/tasmota/language/pt_PT.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/ro_RO.h b/tasmota/language/ro_RO.h
index b6dd915e0..d4ca37c23 100644
--- a/tasmota/language/ro_RO.h
+++ b/tasmota/language/ro_RO.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/ru_RU.h b/tasmota/language/ru_RU.h
index d90cacc8d..25942817c 100644
--- a/tasmota/language/ru_RU.h
+++ b/tasmota/language/ru_RU.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "А"
diff --git a/tasmota/language/sk_SK.h b/tasmota/language/sk_SK.h
index c7d4fb659..aa77fbaef 100644
--- a/tasmota/language/sk_SK.h
+++ b/tasmota/language/sk_SK.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/sv_SE.h b/tasmota/language/sv_SE.h
index 7109033d3..1ff6c8108 100644
--- a/tasmota/language/sv_SE.h
+++ b/tasmota/language/sv_SE.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/tr_TR.h b/tasmota/language/tr_TR.h
index b2a8a0fb3..301feed7e 100644
--- a/tasmota/language/tr_TR.h
+++ b/tasmota/language/tr_TR.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/uk_UA.h b/tasmota/language/uk_UA.h
index 1bc9908c1..044eaf47e 100644
--- a/tasmota/language/uk_UA.h
+++ b/tasmota/language/uk_UA.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE                    "А"
diff --git a/tasmota/language/vi_VN.h b/tasmota/language/vi_VN.h
index 160e6d236..f31be5015 100644
--- a/tasmota/language/vi_VN.h
+++ b/tasmota/language/vi_VN.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/zh_CN.h b/tasmota/language/zh_CN.h
index 26cf0606f..3bfed5647 100644
--- a/tasmota/language/zh_CN.h
+++ b/tasmota/language/zh_CN.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/zh_TW.h b/tasmota/language/zh_TW.h
index 1991ba908..a82028e71 100644
--- a/tasmota/language/zh_TW.h
+++ b/tasmota/language/zh_TW.h
@@ -842,6 +842,7 @@
 #define D_SENSOR_HRG15_RX      "HRG15 Rx"
 #define D_SENSOR_HRG15_TX      "HRG15 Tx"
 #define D_SENSOR_VINDRIKTNING_RX "VINDRIKTNING"
+#define D_SENSOR_HEARTBEAT     "Heartbeat"
 
 // Units
 #define D_UNIT_AMPERE "安培"
diff --git a/tasmota/support_rtc.ino b/tasmota/support_rtc.ino
index fe5fd10ec..03b7164fa 100644
--- a/tasmota/support_rtc.ino
+++ b/tasmota/support_rtc.ino
@@ -377,6 +377,12 @@ void RtcSecond(void)
   static uint32_t last_sync = 0;
   static bool mutex = false;
 
+  if ((TasmotaGlobal.init_state >= INIT_GPIOS) && PinUsed(GPIO_HEARTBEAT)) {
+    digitalWrite(Pin(GPIO_HEARTBEAT), ~TasmotaGlobal.heartbeat_inverted &1);
+    delayMicroseconds(50);
+    digitalWrite(Pin(GPIO_HEARTBEAT), TasmotaGlobal.heartbeat_inverted);
+  }
+
   if (mutex) { return; }
 
   if (Rtc.time_synced) {
diff --git a/tasmota/support_tasmota.ino b/tasmota/support_tasmota.ino
index 4e30671d6..97fba4b6c 100644
--- a/tasmota/support_tasmota.ino
+++ b/tasmota/support_tasmota.ino
@@ -1766,6 +1766,10 @@ void GpioInit(void)
         TasmotaGlobal.ledlnk_inverted = 1;
         mpin -= (AGPIO(GPIO_LEDLNK_INV) - AGPIO(GPIO_LEDLNK));
       }
+      else if (mpin == AGPIO(GPIO_HEARTBEAT_INV)) {
+        TasmotaGlobal.heartbeat_inverted = 1;
+        mpin -= (AGPIO(GPIO_HEARTBEAT_INV) - AGPIO(GPIO_HEARTBEAT));
+      }
       else if ((mpin >= AGPIO(GPIO_PWM1_INV)) && (mpin < (AGPIO(GPIO_PWM1_INV) + MAX_PWMS))) {
         bitSet(TasmotaGlobal.pwm_inverted, mpin - AGPIO(GPIO_PWM1_INV));
         mpin -= (AGPIO(GPIO_PWM1_INV) - AGPIO(GPIO_PWM1));
@@ -1891,6 +1895,11 @@ void GpioInit(void)
 #endif  // ESP8266
   }
 
+  if (PinUsed(GPIO_HEARTBEAT)) {
+    pinMode(Pin(GPIO_HEARTBEAT), OUTPUT);
+    digitalWrite(Pin(GPIO_HEARTBEAT), TasmotaGlobal.heartbeat_inverted);
+  }
+
   // Digital input
   for (uint32_t i = 0; i < MAX_SWITCHES; i++) {
     if (PinUsed(GPIO_INPUT, i)) {
diff --git a/tasmota/tasmota.h b/tasmota/tasmota.h
index ea858c21b..d63d2db80 100644
--- a/tasmota/tasmota.h
+++ b/tasmota/tasmota.h
@@ -278,6 +278,8 @@ enum GetDateAndTimeOptions { DT_LOCAL, DT_UTC, DT_LOCALNOTZ, DT_DST, DT_STD, DT_
 
 enum LoggingLevels {LOG_LEVEL_NONE, LOG_LEVEL_ERROR, LOG_LEVEL_INFO, LOG_LEVEL_DEBUG, LOG_LEVEL_DEBUG_MORE};
 
+enum InitStates {INIT_NONE, INIT_GPIOS, INIT_DONE};
+
 enum WifiConfigOptions {WIFI_RESTART, EX_WIFI_SMARTCONFIG, WIFI_MANAGER, EX_WIFI_WPSCONFIG, WIFI_RETRY, WIFI_WAIT, WIFI_SERIAL, WIFI_MANAGER_RESET_ONLY, MAX_WIFI_OPTION};
 
 enum SwitchModeOptions {TOGGLE, FOLLOW, FOLLOW_INV, PUSHBUTTON, PUSHBUTTON_INV, PUSHBUTTONHOLD, PUSHBUTTONHOLD_INV, PUSHBUTTON_TOGGLE, TOGGLEMULTI,
diff --git a/tasmota/tasmota.ino b/tasmota/tasmota.ino
index b4e13dc30..f873a9fd2 100644
--- a/tasmota/tasmota.ino
+++ b/tasmota/tasmota.ino
@@ -148,6 +148,8 @@ struct TasmotaGlobal_t {
   bool enable_logging;                      // Enable logging
 
   StateBitfield global_state;               // Global states (currently Wifi and Mqtt) (8 bits)
+  uint8_t init_state;                       // Tasmota init state
+  uint8_t heartbeat_inverted;               // Heartbeat pulse inverted flag
   uint8_t spi_enabled;                      // SPI configured
   uint8_t soft_spi_enabled;                 // Software SPI configured
   uint8_t blinks;                           // Number of LED blinks
@@ -430,6 +432,8 @@ void setup(void) {
   XdrvCall(FUNC_PRE_INIT);
   XsnsCall(FUNC_PRE_INIT);
 
+  TasmotaGlobal.init_state = INIT_GPIOS;
+
   SetPowerOnState();
   WifiConnect();
 
diff --git a/tasmota/tasmota_template.h b/tasmota/tasmota_template.h
index 8b5ffae8a..0de887e9c 100644
--- a/tasmota/tasmota_template.h
+++ b/tasmota/tasmota_template.h
@@ -175,6 +175,7 @@ enum UserSelectablePins {
   GPIO_BL0939_RX,                      // BL0939 Serial interface (Dual R3 v2)
   GPIO_BL0942_RX,                      // BL0942 Serial interface
   GPIO_HM330X_SET,                     // HM330X SET pin (sleep when low)
+  GPIO_HEARTBEAT, GPIO_HEARTBEAT_INV,
   GPIO_SENSOR_END };
 
 enum ProgramSelectablePins {
@@ -369,7 +370,8 @@ const char kSensorNames[] PROGMEM =
   D_SENSOR_VINDRIKTNING_RX "|"
   D_SENSOR_BL0939_RX "|"
   D_SENSOR_BL0942_RX "|"
-  D_SENSOR_HM330X_SET
+  D_SENSOR_HM330X_SET "|"
+  D_SENSOR_HEARTBEAT "|" D_SENSOR_HEARTBEAT "_i|"
   ;
 
 const char kSensorNamesFixed[] PROGMEM =
@@ -428,6 +430,8 @@ const uint16_t kGpioNiceList[] PROGMEM = {
 #endif
   AGPIO(GPIO_OUTPUT_HI),                // Fixed output high
   AGPIO(GPIO_OUTPUT_LO),                // Fixed output low
+  AGPIO(GPIO_HEARTBEAT),                 // Every second pulsed high
+  AGPIO(GPIO_HEARTBEAT_INV),             // Every second pulsed low
 #ifdef USE_FTC532
   AGPIO(GPIO_FTC532),                   // FTC532 touch input
 #endif