Standalone-electricity-price-ticker/CHANGELOG.md

Changelog

All notable changes to this project are documented here.

---

v6.1.0 – Midnight Fetch & Market Day Fix (2026‑01‑30)

Summary

This release fixes a bug where the ticker could remain indefinitely on the “No data for today” screen after midnight, even though the API was already returning fresh data. It also refines the after‑midnight retry schedule.

Fixed: Stuck on NO_DATA_OFFSET After Midnight

Problem (v6.0.0):

• After midnight, the device:
  • Detected day rollover and entered a “no data” state.
  • Scheduled an immediate API fetch.
• However:
  • The API can continue to serve yesterday’s market day for some time after local midnight.
  • The code only checked the first unix_seconds entry against the current local day.
  • HTTP + JSON success always incremented apiSuccessCount, even if processJsonData() subsequently decided the dataset was “not for today”.
  • The scheduler treated such fetches as successful, pushed nextScheduledFetchTime 24 hours into the future, and never retried.
  • Result: the ticker stayed on NO_DATA_OFFSET forever, until:
    • A manual long‑press triggered a fresh fetch at a time when the API finally returned recognized “today” data, or
    • The device was rebooted later in the day.

Solution (v6.1.0):

1. Market Day Detection:

   • processJsonData() now determines the “market day” using the last unix_seconds timestamp from the API’s dataset (assumed to cover one full day in 15‑minute steps).
   • It compares that calendar date (local time) against the current local date.
   • If they differ:
     • The dataset is treated as “not for today”.
     • isTodayDataAvailable = false.
     • The function returns false, and a new flag lastProcessJsonAcceptedToday remains false.

2. Logical Failure vs HTTP/JSON Failure:

   • New global flag:
     • lastProcessJsonAcceptedToday – true only when processJsonData() accepts the dataset as “today’s” data.
   • In handleDataFetching():
     • A scheduled fetch is considered a real success only if:
       • HTTP + JSON succeeded, and
       • lastProcessJsonAcceptedToday == true.
     • In all other cases (including “HTTP 200 + parse OK but data still for yesterday”):
       • The fetch is treated as failure for scheduling purposes.
       • If midnightPhaseActive == true, scheduleAfterMidnightFailure() is invoked to plan a retry.

3. Midnight Phase Cleanup:

   • When a fetch finally provides a dataset for today:
     • isTodayDataAvailable = true.
     • lastProcessJsonAcceptedToday = true.
     • midnightPhaseActive is cleared; midnightRetryCount reset to 0.
     • nextScheduledFetchTime is set to 24 hours ahead.

As a result, the ticker will keep retrying after midnight until a correct market‑day dataset appears, instead of giving up after the first HTTP 200.

---

Changed: After‑Midnight Retry Schedule

In scheduleAfterMidnightFailure() the retry strategy when midnightPhaseActive == true has been tuned.

Old behavior (v6.0.0, conceptual):

• First few failures after midnight:
  • Retried every 10 minutes up to 5 attempts.
• Afterwards:
  • Switched to hourly retries (top of each hour).

New behavior (v6.1.0 + user configuration):

• Fast retry phase fully contained within the first hour after midnight.

• You configured:

  if (midnightRetryCount < 2) {
      // Retry every 20 minutes for first 2 attempts (~1 hour window)
      midnightRetryCount++;
      nextScheduledFetchTime = now + 1200; // 20 minutes
      debugPrint(2, "Midnight retry " + String(midnightRetryCount) + "/2 in 20 minutes");
  } else {
      // After that, retry only at top of each hour
      ...
  }
  

• Timeline:

  • 00:00 – initial attempt (triggered by day rollover).
  • If dataset is still for previous day:
    • 1st retry at ~00:20.
    • 2nd retry at ~00:40.
  • After that:
    • Retries only at the top of the next hours (01:00, 02:00, …), until a dataset with market day = today is accepted.

This configuration significantly reduces overnight API load while still ensuring the ticker picks up the new day as soon as the API publishes it.

---

Other Behavior (Retained From v6.0.0)

• NVS caching of daily data:
  • On boot, if NVS contains a dataset whose date matches today’s local date:
    • The JSON is deserialized and processed.
    • A new API call is skipped.
  • After each accepted “today” fetch:
    • Raw JSON payload, date, and a timestamp are stored in NVS.
• Manual long‑press refresh:
  • Still triggers immediate fetch via nextScheduledFetchTime = now;.
  • Now also respects the improved “today” detection; “yesterday’s” data is not accepted as today.
• CET/CEST time handling:
  • Unchanged, still uses TZ_CET_CEST with configTzTime.
• Secondary menu and NVS status lines:
  • Retained from v6.0.0; updated only for version string and minor wording.

---

v6.0.0 – NVS Storage & Daily Fetch (2026‑01‑27)

Summary

First major redesign focused on reducing API traffic and improving resilience using non‑volatile storage.

New

• NVS namespace "my-ticker" introduced with keys:
  • ssid, pass – Wi‑Fi credentials.
  • data_day, data_mon, data_year – stored data calendar day.
  • data_prc – raw JSON string from API.
  • data_last_store – Unix time when data was stored.
• Boot behavior:
  • Try to load and validate NVS data.
  • If date matches today → reuse it and skip initial API call.
• After‑midnight behavior:
  • NVS is overwritten with each successful new‑day dataset.
  • In‑RAM data for yesterday is invalidated at day rollover.

UI / Menu

• Primary list:
  • 15‑minute detail for current hour.
  • Hourly averages for current + next 2 hours.
• Secondary list:
  • Expanded to 20 lines to include:
    • Time/date, last update, daily average.
    • Wi‑Fi RSSI, IP address.
    • API success rate, uptime.
    • NVS status block.
    • Credits & version line.

---

v5.x – Earlier Versions

Earlier versions (v5.x and below) had:

• No NVS‑based caching of daily API data.
• More frequent API calls (e.g., hourly refresh pattern).
• Less robust handling of DST and daily boundaries.

For exact details, see older .ino files and their header comments in this repository.