Add semaphore protection for lastSetupMenuChange

This should prevent the occasional glitching during button setup

Author: PaulZC

Firmware/RTK_Everywhere/RTK_Everywhere.ino

@@ -872,7 +872,40 @@ uint32_t rtcmLastPacketSent; // Time stamp of RTCM going out (to NTRIP Server, E
 
 uint32_t maxSurveyInWait_s = 60L * 15L; // Re-start survey-in after X seconds
 
-uint32_t lastSetupMenuChange; // Limits how much time is spent in the setup menu
+typedef struct {
+    uint32_t timer;
+
+    SemaphoreHandle_t updateSemaphore = NULL;
+
+    void setTimerToMillis()
+    {
+        if (updateSemaphore == NULL)
+            updateSemaphore = xSemaphoreCreateMutex();
+        if (xSemaphoreTake(updateSemaphore, 10 / portTICK_PERIOD_MS) == pdPASS)
+        {
+            timer = millis();
+            xSemaphoreGive(updateSemaphore);
+        }
+    }
+
+    unsigned long millisSinceUpdate()
+    {
+        unsigned long retVal = 0;
+        if (updateSemaphore == NULL)
+            updateSemaphore = xSemaphoreCreateMutex();
+        if (xSemaphoreTake(updateSemaphore, 10 / portTICK_PERIOD_MS) == pdPASS)
+        {
+            retVal = millis() - timer;
+            xSemaphoreGive(updateSemaphore);
+        }
+        return retVal;
+    }
+} semaphoreProtectedTimer;
+// Needs a mutex because the timer is updated by the button task
+// but read by stateUpdate the loop. Prevents a race condition
+// and the occasional glitching seen in the button menu
+semaphoreProtectedTimer lastSetupMenuChange; // Limits how much time is spent in the setup menu
+
 uint32_t lastTestMenuChange;  // Avoids exiting the test menu for at least 1 second
 uint8_t setupSelectedButton =
     0; // In Display Setup, start displaying at this button. This is the selected (highlighted) button.

Firmware/RTK_Everywhere/States.ino

@@ -399,7 +399,7 @@ void stateUpdate()
         break;
 
         case (STATE_DISPLAY_SETUP): {
-            if ((millis() - lastSetupMenuChange) > 10000) // Exit Setup after 10s
+            if (lastSetupMenuChange.millisSinceUpdate() > 10000) // Exit Setup after 10s
             {
                 firstButtonThrownOut = false;
                 changeState(lastSystemState); // Return to the last system state

Firmware/RTK_Everywhere/Tasks.ino

@@ -2183,7 +2183,7 @@ void buttonCheckTask(void *e)
             else if ((systemState == STATE_BASE_NOT_STARTED) && (firstRoverStart == true) &&
                      (buttonPressedFor(500) == true))
             {
-                lastSetupMenuChange = millis(); // Prevent a timeout during state change
+                lastSetupMenuChange.setTimerToMillis(); // Prevent a timeout during state change
                 forceSystemStateUpdate = true;
                 requestChangeState(STATE_TEST);
             }
@@ -2216,7 +2216,7 @@ void buttonCheckTask(void *e)
                 case STATE_NTPSERVER_SYNC:
                     lastSystemState = systemState; // Remember this state to return if needed
                     requestChangeState(STATE_DISPLAY_SETUP);
-                    lastSetupMenuChange = millis();
+                    lastSetupMenuChange.setTimerToMillis();
                     setupSelectedButton = 0; // Highlight the first button
                     showMenu = false;
                     break;
@@ -2225,7 +2225,7 @@ void buttonCheckTask(void *e)
                     // If we are displaying the setup menu, a single tap will cycle through possible system states
                     // Exit into new system state on double tap - see below
                     // Exit display setup into previous state after ~10s - see updateSystemState()
-                    lastSetupMenuChange = millis();
+                    lastSetupMenuChange.setTimerToMillis();
 
                     forceDisplayUpdate = true; // User is interacting so repaint display quickly
 
@@ -2262,7 +2262,7 @@ void buttonCheckTask(void *e)
 
                 case STATE_TESTING:
                     // If we are in testing, return to Base Not Started
-                    lastSetupMenuChange = millis(); // Prevent a timeout during state change
+                    lastSetupMenuChange.setTimerToMillis(); // Prevent a timeout during state change
                     baseCasterDisableOverride();    // Leave Caster mode
                     requestChangeState(STATE_BASE_NOT_STARTED);
                     break;
@@ -2287,7 +2287,7 @@ void buttonCheckTask(void *e)
                     // If we are displaying the setup menu, a single tap will cycle through possible system states - see
                     // above Exit into new system state on double tap Exit display setup into previous state after ~10s
                     // - see updateSystemState()
-                    lastSetupMenuChange = millis(); // Prevent a timeout during state change
+                    lastSetupMenuChange.setTimerToMillis(); // Prevent a timeout during state change
                     uint8_t thisIsButton = 0;
                     for (auto it = setupButtons.begin(); it != setupButtons.end(); it = std::next(it))
                     {