From a30311caedde2599b3da9da0a4268c40f4fcdec5 Mon Sep 17 00:00:00 2001
From: Sergei Kotlyachkov <kotl@2x2.cc>
Date: Thu, 9 Nov 2023 21:16:17 -0500
Subject: [PATCH] Refactor usage of delay() into an Helper IO class that
 schedules pin bouncing back

---
 IO_ScheduledPin.h | 115 ++++++++++++++++++++++++++++++++++++++++++++++
 Turnouts.cpp      |  19 ++++++--
 2 files changed, 131 insertions(+), 3 deletions(-)
 create mode 100644 IO_ScheduledPin.h

diff --git a/IO_ScheduledPin.h b/IO_ScheduledPin.h
new file mode 100644
index 0000000..e9040e8
--- /dev/null
+++ b/IO_ScheduledPin.h
@@ -0,0 +1,115 @@
+/*
+ *  © 2023, Sergei Kotlyachkov. All rights reserved.
+ *
+ *  This file is part of DCC++EX API
+ *
+ *  This is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  It is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with CommandStation.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+
+#ifndef IO_SCHEDULED_PIN_H
+#define IO_SCHEDULED_PIN_H
+
+#include "IODevice.h"
+#include <Arduino.h>
+#include "defines.h"
+
+/**
+ * Bounces back single Arduino Pin to specified state after set period of time.
+ *
+ * It will establish itself as owner of the pin over ArduinoPins class that typically responds to it and
+ * activates itself during loop() phase. It restores scheduled state and does not try again until
+ * another write()
+ *
+ * Example usage:
+ * Create: ScheduledPin::create(5, LOW, 20000);
+ *
+ * Then, when neeeded, just call:
+ * IODevice::write(5, HIGH); // this will call fastWriteDigital(5, HIGH)
+ *
+ * In 20 milliseconds, it will also call fastWriteDigital(5, LOW)
+ *
+ * In edge case where write() is called twice before responding in the loop,
+ * the schedule will restart and double the bounce back time.
+ */
+class ScheduledPin : public IODevice {
+private:
+  int _scheduledValue;
+  uint32_t _durationMicros;
+
+public:
+  //  Static function to handle create calls.
+  static void create(VPIN pin, int scheduledValue, uint32_t durationMicros) {
+    new ScheduledPin(pin, scheduledValue, durationMicros);
+  }
+
+protected:
+  // Constructor.
+  ScheduledPin(VPIN pin, int scheduledValue, uint32_t durationMicros) : IODevice(pin, 1)  {
+    _scheduledValue = scheduledValue;
+    _durationMicros = durationMicros;
+    // Typically returned device will be ArduinoPins
+    IODevice* controlledDevice = IODevice::findDevice(pin);
+    if (controlledDevice != NULL) {
+      addDevice(this, controlledDevice);
+    }
+    else {
+      DIAG(F("ScheduledPin Controlled device not found for pin:%d"), pin);
+      _deviceState = DEVSTATE_FAILED;
+    }
+  }
+
+  // Device-specific initialisation
+  void _begin() override {
+    #ifdef DIAG_IO
+    _display();
+    #endif
+    pinMode(_firstVpin, OUTPUT);
+    ArduinoPins::fastWriteDigital(_firstVpin, _scheduledValue);
+  }
+
+  void _write(VPIN vpin, int value) override {
+    if (_deviceState == DEVSTATE_FAILED) return;
+    if (vpin != _firstVpin) {
+      #ifdef DIAG_IO
+      DIAG(F("ScheduledPin Error VPIN:%u not equal to %u"), vpin, _firstVpin);
+      #endif
+      return;
+    }
+    #ifdef DIAG_IO
+    DIAG(F("ScheduledPin Write VPIN:%u Value:%d"), vpin, value);
+    #endif
+    unsigned long currentMicros = micros();
+    delayUntil(currentMicros + _durationMicros);
+    ArduinoPins::fastWriteDigital(_firstVpin, value);
+  }
+
+
+  void _loop(unsigned long currentMicros) {
+    if (_deviceState == DEVSTATE_FAILED) return;
+    #ifdef DIAG_IO
+    DIAG(F("ScheduledPin Write VPIN:%u Value:%d"), _firstVpin, _scheduledValue);
+    #endif
+    ArduinoPins::fastWriteDigital(_firstVpin, _scheduledValue);
+    delayUntil(currentMicros + 0x7fffffff); // Largest time in the future!  Effectively disable _loop calls.
+  }
+
+  // Display information about the device, and perhaps its current condition (e.g. active, disabled etc).
+  void _display() {
+    DIAG(F("ScheduledPin Configured:%u value=%d duration=%ld"), (int)_firstVpin,
+      (int)_firstVpin, _scheduledValue, _durationMicros);
+  }
+};
+
+#endif // IO_SCHEDULED_PIN_H
diff --git a/Turnouts.cpp b/Turnouts.cpp
index 4b44ad4..5957d50 100644
--- a/Turnouts.cpp
+++ b/Turnouts.cpp
@@ -36,6 +36,10 @@
 #include "LCN.h"
 #ifdef EESTOREDEBUG
 #include "DIAG.h"
+#endif
+
+#ifndef IO_NO_HAL
+#include "IO_ScheduledPin.h"
 #endif
 
   /* 
@@ -493,6 +497,14 @@
     _hbridgeTurnoutData.pin1 = pin1;
     _hbridgeTurnoutData.pin2 = pin2;
     _hbridgeTurnoutData.millisDelay = millisDelay;
+#ifndef IO_NO_HAL
+    // HARD LIMIT to maximum 0.5 second to avoid burning the coil
+    // Also note 1000x multiplier because ScheduledPin works with microSeconds.
+    ScheduledPin::create(pin1, LOW, 1000*min(millisDelay, 500));
+    ScheduledPin::create(pin2, LOW, 1000*min(millisDelay, 500));
+#else
+    DIAG(F("H-Brdige Turnout %d will be disabled because HAL is off"), id);
+#endif
   }
 
   // Create function
@@ -545,10 +557,11 @@
   void HBridgeTurnout::turnUpDown(VPIN pin) {
     // HBridge turnouts require very small, prescribed time to keep pin1 or pin2 in HIGH state.
     // Otherwise internal coil of the turnout will burn.
+    // If HAL is disabled (and therefore SchedulePin class), we can not turn this on,
+    // otherwise coil will burn and device will be lost.
+#ifndef IO_NO_HAL
     IODevice::write(pin, HIGH);
-    // HARD LIMIT to maximum 0.5 second to avoid burning the coil
-    delay(min(_hbridgeTurnoutData.millisDelay, 500));
-    IODevice::write(pin, LOW);
+#endif
   }
 
   bool HBridgeTurnout::setClosedInternal(bool close) {