Update README for version 6.2.4 release

Updated version number to 6.2.4 and added highlights for the new version, including a critical bug fix related to display refresh at exact hour boundaries.

CHANGELOG.md

@@ -2,6 +2,20 @@
 
 All notable changes to this project are documented here.
 
+## v6.2.4 - Exact-boundary display refresh bug (2026-04-01):
+
+**Summary**
+
+Top of the hour auto display refresh glitch fix where display automatically refreshed but showed the PREVIOUS hour's data.
+
+### Problem: 
+- At the exact top of the hour (e.g., 20:00:00), the display automatically refreshed but showed the PREVIOUS hour's data (19:00). This happened because the "next-boundary" rounding logic in findCurrentPriceIndex() incorrectly excluded the current interval if the time was exactly on the boundary.
+
+### Solution: 
+- Simplified findCurrentPriceIndex() to use a robust "last entry <= now" comparison. This ensures the display transitions to the new hour instantaneously at XX:00:00.
+
+---
+
 ## v6.2.3 - State-based display refresh logic fix (2026-04-01):
 
 **Summary**

README.md

@@ -11,12 +11,16 @@ This project is an Arduino‑IDE‑friendly firmware for the **Seeed XIAO ESP32
 - Uses a white LED and an optional presence sensor to give quick visual feedback.
 - Stores daily price data in **NVS** to survive reboots and reduce API calls.
 
-The latest sketch implements **Version 6.2.3**.
+The latest sketch implements **Version 6.2.4**.
 
 ---
 
 ## Version Highlights
 
+### v6.2.4 - Exact-boundary display refresh bug  (critical fix of v6.2.3 update)
+- Problem: At the exact top of the hour (e.g., 20:00:00), the display automatically refreshed but showed the PREVIOUS hour's data (19:00). This happened because the "next-boundary" rounding logic in findCurrentPriceIndex() incorrectly excluded the current interval if the time was exactly on the boundary.
+- Fix: Simplified findCurrentPriceIndex() to use a robust "last entry <= now" comparison. This ensures the display transitions to the new hour instantaneously at XX:00:00.
+
 ### v6.2.3 - State-based display refresh logic  (critical fix of v6.2.2 update)
 - Problem: Screen would occasionally fail to update if the ESP32 was busy (fetching data or reconnecting WiFi) during the exact 00/15/30/45 minute mark.
 - Fix: Switched from "Event-Based" (refresh only AT minute X) to "State-Based" (refresh IF current time != last refresh time). This ensures the screen updates immediately even if the device was busy during the transition.

VERSION.md

@@ -2,13 +2,19 @@
 
 ## Current firmware
 
-- **Version:** 6.2.3
+- **Version:** 6.2.4
 - **Release date:** 2026-04-01
 - **Target MCU:** Seeed XIAO ESP32‑C3
 - **Display:** 20x4 I²C LCD (PCF8574, default address `0x27`)
 - **API endpoint:** `https://api.energy-charts.info/price?bzn=SI`
 - **Resolution:** 15‑minute intervals, hourly averages for overview
 
+ ## Highlights of v6.2.4
+
+ - **BUG FIX:** Exact-boundary display refresh bug
+ - Problem: At the exact top of the hour (e.g., 20:00:00), the display automatically refreshed but showed the PREVIOUS hour's data (19:00). This happened because the "next-boundary" rounding logic in findCurrentPriceIndex() incorrectly excluded the current interval if the time was exactly on the boundary.
+ - Fix: Simplified findCurrentPriceIndex() to use a robust "last entry <= now" comparison. This ensures the display transitions to the new hour instantaneously at XX:00:00.
+
  ## Highlights of v6.2.3
 
 - **BUG FIX**: State-based display refresh logic