From 385a89507bca7ef11eaf0c0f103a705ceb3f0729 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 25 Jun 2023 10:45:37 -0500
Subject: [PATCH] Fix crash when flash is written too frequently (#18)

---
 base.yaml                    |  3 +++
 components/ratgdo/ratgdo.cpp | 29 ++++++++++++++++-------------
 components/ratgdo/ratgdo.h   |  4 ++--
 3 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/base.yaml b/base.yaml
index 05a998b..3997d50 100644
--- a/base.yaml
+++ b/base.yaml
@@ -6,6 +6,9 @@ external_components:
       url: https://github.com/esphome-ratgdo/esphome-ratgdo
     refresh: 1s
 
+preferences:
+  flash_write_interval: 5s
+
 ratgdo:
   id: ${id_prefix}
   input_gdo_pin: ${uart_rx_pin}
diff --git a/components/ratgdo/ratgdo.cpp b/components/ratgdo/ratgdo.cpp
index 4d5e17a..ad5e992 100644
--- a/components/ratgdo/ratgdo.cpp
+++ b/components/ratgdo/ratgdo.cpp
@@ -22,7 +22,17 @@ namespace ratgdo {
 
     static const char* const TAG = "ratgdo";
     static const int SYNC_DELAY = 2000;
-    static const uint8_t MAX_CODES_WITHOUT_FLASH_WRITE = 3;
+    //
+    // MAX_CODES_WITHOUT_FLASH_WRITE is a bit of a guess
+    // since we write the flash at most every every 5s
+    //
+    // We want the rolling counter to be high enough that the
+    // GDO will accept the command after an unexpected reboot
+    // that did not save the counter to flash in time which
+    // results in the rolling counter being behind what the GDO
+    // expects.
+    //
+    static const uint8_t MAX_CODES_WITHOUT_FLASH_WRITE = 5;
     static const uint32_t FLASH_WRITE_INTERVAL = 10000;
 
     void IRAM_ATTR HOT RATGDOStore::isrObstruction(RATGDOStore* arg)
@@ -55,9 +65,6 @@ namespace ratgdo {
 
         this->input_obst_pin_->attach_interrupt(RATGDOStore::isrObstruction, &this->store_, gpio::INTERRUPT_ANY_EDGE);
 
-        // save counter to flash every 10s if it changed
-        set_interval(FLASH_WRITE_INTERVAL, std::bind(&RATGDOComponent::saveCounter, this, 1));
-
         ESP_LOGV(TAG, "Syncing rolling code counter after reboot...");
 
         // many things happening at startup, use some delay for sync
@@ -447,7 +454,7 @@ namespace ratgdo {
         delayMicroseconds(1260); // "LOW" pulse duration before the message start
         this->swSerial.write(this->txRollingCode, CODE_LENGTH);
 
-        saveCounter(MAX_CODES_WITHOUT_FLASH_WRITE);
+        saveCounter();
     }
 
     void RATGDOComponent::sync()
@@ -545,16 +552,12 @@ namespace ratgdo {
         transmit(command::LOCK, data::TOGGLE);
     }
 
-    void RATGDOComponent::saveCounter(int threshold)
+    void RATGDOComponent::saveCounter()
     {
         this->pref_.save(&this->rollingCodeCounter);
-        if (!this->lastSyncedRollingCodeCounter || this->rollingCodeCounter - this->lastSyncedRollingCodeCounter >= threshold) {
-            // do flash write outside of the component loop
-            defer([=] {
-                this->lastSyncedRollingCodeCounter = this->rollingCodeCounter;
-                global_preferences->sync();
-            });
-        }
+        // Forcing a sync results in a soft reset if there are too many
+        // writes to flash in a short period of time. To avoid this,
+        // we have configured preferences to write every 5s
     }
 
     void RATGDOComponent::register_child(RATGDOClient* obj)
diff --git a/components/ratgdo/ratgdo.h b/components/ratgdo/ratgdo.h
index e47fd86..6503480 100644
--- a/components/ratgdo/ratgdo.h
+++ b/components/ratgdo/ratgdo.h
@@ -160,7 +160,7 @@ namespace ratgdo {
         void obstructionLoop();
         void statusUpdateLoop();
 
-        void saveCounter(int threshold);
+        void saveCounter();
 
         void doorCommand(uint32_t data);
 
@@ -176,7 +176,7 @@ namespace ratgdo {
         void toggleLock();
         void lock();
         void unlock();
-        
+
         void query_status();
         void query_openings();