Use rollover count at the time of the event, not the current value to

produce correct dates. Use 64-bit integers for timestamp to ease
arithmetic.

Software/Software.ino

@@ -339,6 +339,15 @@ void init_serial() {
 #endif  // DEBUG_VIA_USB
 }
 
+void update_overflow(unsigned long currentMillis) {
+  // Check if millis overflowed
+  if (currentMillis < lastMillisOverflowCheck) {
+    // We have overflowed, increase rollover count
+    datalayer.system.status.millisrolloverCount++;
+  }
+  lastMillisOverflowCheck = currentMillis;
+}
+
 void check_interconnect_available() {
   if (datalayer.battery.status.voltage_dV == 0 || datalayer.battery2.status.voltage_dV == 0) {
     return;  // Both voltage values need to be available to start check
@@ -519,11 +528,8 @@ void update_calculated_values() {
       datalayer.battery.status.reported_remaining_capacity_Wh = datalayer.battery2.status.remaining_capacity_Wh;
     }
   }
-  // Check if millis has overflowed. Used in events to keep better track of time
+
-  if (currentMillis < lastMillisOverflowCheck) {  // Overflow detected
+  update_overflow(currentMillis);  // Update millis rollover count
-    datalayer.system.status.millisrolloverCount++;
-  }
-  lastMillisOverflowCheck = currentMillis;
 }
 
 void check_reset_reason() {
@@ -581,3 +587,9 @@ void check_reset_reason() {
       break;
   }
 }
+
+uint64_t get_timestamp(unsigned long currentMillis) {
+  update_overflow(currentMillis);
+  return (uint64_t)datalayer.system.status.millisrolloverCount * (uint64_t)std::numeric_limits<uint32_t>::max() +
+         (uint64_t)currentMillis;
+}

Software/src/devboard/utils/events.cpp

@@ -3,13 +3,6 @@
 
 #include "../../../USER_SETTINGS.h"
 
-typedef struct {
-  EVENTS_ENUM_TYPE event;
-  uint8_t millisrolloverCount;
-  uint32_t timestamp;
-  uint8_t data;
-} EVENT_LOG_ENTRY_TYPE;
-
 typedef struct {
   EVENTS_STRUCT_TYPE entries[EVENT_NOF_EVENTS];
   EVENTS_LEVEL_TYPE level;
@@ -30,7 +23,6 @@ void init_events(void) {
   for (uint16_t i = 0; i < EVENT_NOF_EVENTS; i++) {
     events.entries[i].data = 0;
     events.entries[i].timestamp = 0;
-    events.entries[i].millisrolloverCount = 0;
     events.entries[i].occurences = 0;
     events.entries[i].MQTTpublished = false;  // Not published by default
   }
@@ -155,7 +147,6 @@ void reset_all_events() {
     events.entries[i].data = 0;
     events.entries[i].state = EVENT_STATE_INACTIVE;
     events.entries[i].timestamp = 0;
-    events.entries[i].millisrolloverCount = 0;
     events.entries[i].occurences = 0;
     events.entries[i].MQTTpublished = false;  // Not published by default
   }
@@ -396,6 +387,8 @@ EVENTS_LEVEL_TYPE get_event_level(void) {
   return events.level;
 }
 
+uint64_t get_timestamp(unsigned long currentMillis);
+
 /* Local functions */
 
 static void set_event(EVENTS_ENUM_TYPE event, uint8_t data, bool latched) {
@@ -416,8 +409,7 @@ static void set_event(EVENTS_ENUM_TYPE event, uint8_t data, bool latched) {
   }
 
   // We should set the event, update event info
-  events.entries[event].timestamp = millis();
+  events.entries[event].timestamp = get_timestamp(millis());
-  events.entries[event].millisrolloverCount = datalayer.system.status.millisrolloverCount;
   events.entries[event].data = data;
   // Check if the event is latching
   events.entries[event].state = latched ? EVENT_STATE_ACTIVE_LATCHED : EVENT_STATE_ACTIVE;
@@ -448,17 +440,11 @@ static void update_bms_status(void) {
 
 // Function to compare events by timestamp descending
 bool compareEventsByTimestampDesc(const EventData& a, const EventData& b) {
-  if (a.event_pointer->millisrolloverCount != b.event_pointer->millisrolloverCount) {
-    return a.event_pointer->millisrolloverCount > b.event_pointer->millisrolloverCount;
-  }
   return a.event_pointer->timestamp > b.event_pointer->timestamp;
 }
 
 // Function to compare events by timestamp ascending
 bool compareEventsByTimestampAsc(const EventData& a, const EventData& b) {
-  if (a.event_pointer->millisrolloverCount != b.event_pointer->millisrolloverCount) {
-    return a.event_pointer->millisrolloverCount < b.event_pointer->millisrolloverCount;
-  }
   return a.event_pointer->timestamp < b.event_pointer->timestamp;
 }
 

Software/src/devboard/utils/events.h

@@ -129,12 +129,11 @@ typedef enum {
 } EVENTS_STATE_TYPE;
 
 typedef struct {
-  uint32_t timestamp;           // Time in seconds since startup when the event occurred
+  uint64_t timestamp;
-  uint8_t millisrolloverCount;  // number of times millis rollovers before timestamp
+  uint8_t data;             // Custom data passed when setting the event, for example cell number for under voltage
-  uint8_t data;                 // Custom data passed when setting the event, for example cell number for under voltage
+  uint8_t occurences;       // Number of occurrences since startup
-  uint8_t occurences;           // Number of occurrences since startup
+  EVENTS_LEVEL_TYPE level;  // Event level, i.e. ERROR/WARNING...
-  EVENTS_LEVEL_TYPE level;      // Event level, i.e. ERROR/WARNING...
+  EVENTS_STATE_TYPE state;  // Event state, i.e. ACTIVE/INACTIVE...
-  EVENTS_STATE_TYPE state;      // Event state, i.e. ACTIVE/INACTIVE...
   bool MQTTpublished;
 } EVENTS_STRUCT_TYPE;
 

Software/src/devboard/webserver/events_html.cpp

@@ -1,4 +1,5 @@
 #include "events_html.h"
+#include <limits>
 #include "../../datalayer/datalayer.h"
 
 const char EVENTS_HTML_START[] = R"=====(
@@ -10,7 +11,9 @@ const char EVENTS_HTML_END[] = R"=====(
 button:hover { background-color: #3A4A52; }</style>
 <button onclick="askClear()">Clear all events</button>
 <button onclick="home()">Back to main page</button>
-<style>.event:nth-child(even){background-color:#455a64}.event:nth-child(odd){background-color:#394b52}</style><script>function showEvent(){document.querySelectorAll(".event").forEach(function(e){var n=e.querySelector(".sec-ago");n&&(n.innerText=new Date(Date.now()-(4294967296*+n.innerText.split(";")[0]+ +n.innerText.split(";")[1])).toLocaleString())})}function askClear(){window.confirm("Are you sure you want to clear all events?")&&(window.location.href="/clearevents")}function home(){window.location.href="/"}window.onload=function(){showEvent()}</script>
+<style>.event:nth-child(even){background-color:#455a64}.event:nth-child(odd){background-color:#394b52}</style>
+<script>function showEvent(){document.querySelectorAll(".event").forEach(function(e){var n=e.querySelector(".sec-ago");n&&(n.innerText=new Date(Number(BigInt(Date.now()) - BigInt(n.innerText))).toLocaleString())})}function askClear(){window.confirm("Are you sure you want to clear all events?")&&(window.location.href="/clearevents")}function home(){window.location.href="/"}window.onload=function(){showEvent()}
+</script>
 )=====";
 
 static std::vector<EventData> order_events;
@@ -34,12 +37,15 @@ String events_processor(const String& var) {
     }
     // Sort events by timestamp
     std::sort(order_events.begin(), order_events.end(), compareEventsByTimestampDesc);
-    unsigned long timestamp_now = millis();
+    uint64_t current_timestamp =
+        (uint64_t)datalayer.system.status.millisrolloverCount * (uint64_t)std::numeric_limits<uint32_t>::max() +
+        (uint64_t)millis();
 
     // Generate HTML and debug output
     for (const auto& event : order_events) {
       EVENTS_ENUM_TYPE event_handle = event.event_handle;
       event_pointer = event.event_pointer;
+
 #ifdef DEBUG_LOG
       logging.println("Showing Event: " + String(get_event_enum_string(event_handle)) +
                       " count: " + String(event_pointer->occurences) + " seconds: " + String(event_pointer->timestamp) +
@@ -49,8 +55,8 @@ String events_processor(const String& var) {
       content.concat("<div class='event'>");
       content.concat("<div>" + String(get_event_enum_string(event_handle)) + "</div>");
       content.concat("<div>" + String(get_event_level_string(event_handle)) + "</div>");
-      content.concat("<div class='sec-ago'>" + String(datalayer.system.status.millisrolloverCount) + ";" +
+      // Frontend expects to see time difference (in ms) from now to event
-                     String(timestamp_now - event_pointer->timestamp) + "</div>");
+      content.concat("<div class='sec-ago'>" + String(current_timestamp - event_pointer->timestamp) + "</div>");
       content.concat("<div>" + String(event_pointer->occurences) + "</div>");
       content.concat("<div>" + String(event_pointer->data) + "</div>");
       content.concat("<div>" + String(get_event_message_string(event_handle)) + "</div>");
@@ -80,7 +86,7 @@ String events_processor(const String& var) {
     function showEvent() {
         document.querySelectorAll(".event").forEach(function (e) {
             var n = e.querySelector(".sec-ago");
-            n && (n.innerText = new Date(Date.now() - (+n.innerText.split(";")[0] * 4294967296 + +n.innerText.split(";")[1])).toLocaleString());
+            n && (n.innerText = new Date(Number(BigInt(Date.now()) - BigInt(n.innerText))).toLocaleString());
         });
     }
     function askClear() {