ESPTimeCast - WiFi-connected LED clock and weather station

ESPTimeCast is a WiFi-connected LED matrix clock and weather station based on ESP8266/ESP32 and MAX7219.It displays the current time, day of the week, and local weather (temp/humidity/weather description) fetched from OpenWeatherMap.Setup and configuration are fully managed via a built-in web interface.

3D Printable Case

Want to give your ESPTimeCast a home? You can 3D print a custom case for it!A styilish version (V2) of the case has just been released!The case front panel (3mm) can be laser cut!

Get yours here:

• Printables
• Cults3D

📰 Press Mentions

ESPTimeCast has been featured on:

• Hackaday
• XDA Developers

Features

• LED Matrix Display (8x32) powered by MAX7219, with custom font support
• Simple Web Interface for all configuration (WiFi, weather, time zone, display durations, and more)
• Automatic NTP Sync with robust status feedback and retries
• Weather Fetching from OpenWeatherMap (every 5 minutes, temp/humidity/description)
• Fallback AP Mode for easy first-time setup or configuration
• Timezone Selection from IANA names (DST integrated on backend)
• Get My Location button to get your approximate Lat/Long.
• Week Day and Weather Description display in multiple languages
• Persistent Config stored in LittleFS, with backup/restore system
• Status Animations for WiFi connection, AP mode, time syncing.

Advanced Settings panel with:

• Custom Primary/Secondary NTP server input
• Display Day of the Week toggle (default is on)
• Display Blinking Colon toggle (default is on)
• Show Date toggle (default is off)
• 24/12h clock mode toggle (24-hour default)
• Imperial Units (°F) toggle (metric °C defaults)
• Show Humidity toggle (display Humidity besides Temperature)
• Weather description toggle (displays: heavy rain, scattered clouds, thunderstorm etc.)
• Flip display (180 degrees)
• Adjustable display brightness
• Dimming Hours Scheduling
• Countdown function (Scroll / Dramatic)
• Optional glucose + trend display (Nightscout-compatible, set via ntpserver2)
• Advanced Settings panel with:Custom Primary/Secondary NTP server inputDisplay Day of the Week toggle (default is on)Display Blinking Colon toggle (default is on)Show Date toggle (default is off)24/12h clock mode toggle (24-hour default)Imperial Units (°F) toggle (metric °C defaults)Show Humidity toggle (display Humidity besides Temperature)Weather description toggle (displays: heavy rain, scattered clouds, thunderstorm etc.)Flip display (180 degrees)Adjustable display brightnessDimming Hours SchedulingCountdown function (Scroll / Dramatic)Optional glucose + trend display (Nightscout-compatible, set via ntpserver2)

Wiring

Power Supply Change Switching from 3.3V to 5V for Display

Note: Pins are in the same position but make sure the right declaration in in your sketch

D1 Mini → MAX7219

GND GND

5V VCC

D5 CLK

D7 CS

D8 DIN

Tip: Always double-check that VCC (5 V), GND, and DIN/CS/CLK match your MAX7219 module’s pin order — different modules sometimes label them differently.For other Wemos boards check the official GitHub Repo

Important hardware update:Pins have been update to be solder in the same place for all the Wemos boards, Check your board version and update the sketch accordingly. After observing overheating issues and unstable behavior when powering the MAX7219 matrix from the Mini D1’s 3.3V pin, we’re officially switching to powering the display via the 5V USB rail instead.

What’s changing:

• Before: Display VCC was connected to 3.3V pin on the ESP board.
• Now: Display VCC will be connected to the board’s 5V pin (which comes directly from USB power).

Why this change is needed:

• The MAX7219 LED matrix is designed for 5V operation.
• The onboard 3.3V regulator (usually an AMS1117) on the Mini D1 is very limited in current output (~800mA max, often much less in practice).

High-brightness matrix modules — especially green/yellow displays — can draw enough current to overload the regulator, causing:

• Overheating
• Voltage drop
• Complete regulator failure (some users reported only 2.4V output after damage)
• High-brightness matrix modules — especially green/yellow displays — can draw enough current to overload the regulator, causing:OverheatingVoltage dropComplete regulator failure (some users reported only 2.4V output after damage)

Benefits of using 5V:

• Higher brightness and more stable matrix performance
• Reduced heat load on the ESP8266 board
• Avoid long-term damage to the onboard regulator
• The MAX7219 works fine with 3.3V logic signals from the ESP (no need for level shifters)

Web UI & Configuration

The built-in web interface provides full configuration for:

• WiFi settings (SSID & Password)
• Weather settings (OpenWeatherMap API key, City, Country, Coordinates)
• Time zone (will auto-populate if TZ is found)
• Day of the Week and Weather Description languages
• Display durations for clock and weather (milliseconds)
• Advanced Settings (see below)

First-time Setup / AP Mode

Power on the device. If WiFi fails, it auto-starts in AP mode:

• SSID:ESPTimeCast
• Password:12345678
• Captive portal should open automatically, if it doesn't open http://192.168.4.1 or http://setup.esp in your browser.
• Power on the device. If WiFi fails, it auto-starts in AP mode:SSID:ESPTimeCast
Password:12345678
Captive portal should open automatically, if it doesn't open http://192.168.4.1 or http://setup.esp in your browser.
• Set your WiFi and all other options.
• Click Save Setting – the device saves config, reboots, and connects.
• The device shows its local IP address after boot so you can login again for setting changes

*External links and the "Get My Location" button require internet access.They won't work while the device is in AP Mode - connect to Wi-Fi first.

UI Example:

Advanced Settings

Click the cog icon next to “Advanced Settings” in the web UI to reveal extra configuration options.

Available advanced settings:

• Primary NTP Server: Override the default NTP server (e.g. pool.ntp.org)
• Secondary NTP Server: Fallback NTP server (e.g. time.nist.gov)
• Day of the Week: Display Day of the Week in the desired language
• Blinking Colon toggle (default is on)
• Show Date (default is off, duration is the same as weather duration)
• 24/12h Clock: Switch between 24-hour and 12-hour time formats (24-hour default)
• Imperial Units (°F) toggle (metric °C defaults)
• Humidity: Display Humidity besides Temperature
• Weather description toggle (display weather description in the selected language* for 3 seconds or scrolls once if description is too long)
• Flip Display: Invert the display vertically/horizontally
• Brightness: Off - 0 (dim) to 15 (bright)
• Dimming Feature: Start time, end time and desired brightness selection
• Countdown function, set a countdown to your favorit/next event, 2 modes: Scroll/Dramatic!

*Non-English characters converted to their closest English alphabet.*For Esperanto, Irish, and Swahili, weather description translations are not available. Japanese translations exist, but since the device cannot display all Japanese characters, English will be used in all these cases.

Tip: Don't forget to press the save button to keep your settings

Configuration Notes

• OpenWeatherMap API Key:
• Make an account here
• Check your API key here
• City Name: e.g. Tokyo, London, etc.
• Country Code: 2-letter code (e.g., JP, GB)
• ZIP Code: Enter your ZIP code in the city field and US in the country field (US only)
• Latitude and Longitude You can enter coordinates in the city field (lat.) and country field (long.)
• Time Zone: Select from IANA zones (e.g., America/New_York, handles DST automatically)

Getting Started

This guide will walk you through setting up your environment and uploading the ESPTimeCast project to your ESP8266 or ESP32 board. Please follow the instructions carefully for your specific board type.

ESP8266 Setup

Follow these steps to prepare your Arduino IDE for ESP8266 development:

Install ESP8266 Board Package:

• Open File > Preferences in Arduino IDE.
• Add http://arduino.esp8266.com/stable/package_esp8266com_index.json to "Additional Boards Manager URLs."
• Go to Tools > Board > Boards Manager.... Search for esp8266 by ESP8266 Community and click "Install".
• Install ESP8266 Board Package:Open File > Preferences in Arduino IDE.Add http://arduino.esp8266.com/stable/package_esp8266com_index.json to "Additional Boards Manager URLs."Go to Tools > Board > Boards Manager.... Search for esp8266 by ESP8266 Community and click "Install".

Select Your Board:

• Go to Tools > Board and select your specific board, e.g., Wemos D1 Mini (or your ESP8266 variant).
• Select Your Board:Go to Tools > Board and select your specific board, e.g., Wemos D1 Mini (or your ESP8266 variant).

Configure Flash Size:

• Under Tools, select Flash Size "4MB FS:2MB OTA:~1019KB". This ensures enough space for the sketch and LittleFS data.
• Configure Flash Size:Under Tools, select Flash Size "4MB FS:2MB OTA:~1019KB". This ensures enough space for the sketch and LittleFS data.

Install Libraries:

Go to Sketch > Include Library > Manage Libraries... and install the following:

• ArduinoJson by Benoit Blanchon
• MD_Parola by majicDesigns (this will typically also install its dependency: MD_MAX72xx)
• ESPAsyncTCP by ESP32Async
• ESPAsyncWebServer by ESP32Async
• Go to Sketch > Include Library > Manage Libraries... and install the following:ArduinoJson by Benoit BlanchonMD_Parola by majicDesigns (this will typically also install its dependency: MD_MAX72xx)ESPAsyncTCP by ESP32AsyncESPAsyncWebServer by ESP32Async
• Install Libraries:Go to Sketch > Include Library > Manage Libraries... and install the following:ArduinoJson by Benoit BlanchonMD_Parola by majicDesigns (this will typically also install its dependency: MD_MAX72xx)ESPAsyncTCP by ESP32AsyncESPAsyncWebServer by ESP32Async

ESP32 Setup

Follow these steps to prepare your Arduino IDE for ESP32 development:

Install ESP32 Board Package:

• Go to Tools > Board > Boards Manager.... Search for esp32 by Espressif Systems and click "Install".
• Install ESP32 Board Package:Go to Tools > Board > Boards Manager.... Search for esp32 by Espressif Systems and click "Install".

Select Your Board:

• Go to Tools > Board and select your specific board, e.g., LOLIN S2 Mini (or your ESP32 variant).
• Select Your Board:Go to Tools > Board and select your specific board, e.g., LOLIN S2 Mini (or your ESP32 variant).

Configure Partition Scheme:

• Under Tools, select Partition Scheme "Default 4MB with spiffs". This ensures enough space for the sketch and LittleFS data.
• Configure Partition Scheme:Under Tools, select Partition Scheme "Default 4MB with spiffs". This ensures enough space for the sketch and LittleFS data.

Install Libraries:

Go to Sketch > Include Library > Manage Libraries... and install the following:

• ArduinoJson by Benoit Blanchon
• MD_Parola by majicDesigns (this will typically also install its dependency: MD_MAX72xx)
• AsyncTCP by ESP32Async
• ESPAsyncWebServer by ESP32Async
• Go to Sketch > Include Library > Manage Libraries... and install the following:ArduinoJson by Benoit BlanchonMD_Parola by majicDesigns (this will typically also install its dependency: MD_MAX72xx)AsyncTCP by ESP32AsyncESPAsyncWebServer by ESP32Async
• Install Libraries:Go to Sketch > Include Library > Manage Libraries... and install the following:ArduinoJson by Benoit BlanchonMD_Parola by majicDesigns (this will typically also install its dependency: MD_MAX72xx)AsyncTCP by ESP32AsyncESPAsyncWebServer by ESP32Async

Uploading the Code and Data

Once your Arduino IDE is set up for your board (as described above):

Open the Project Folder:

• For ESP8266: Navigate to and open the ESPTimceCast_ESP8266 project folder. Inside, you'll find the main sketch file, typically named ESPTimceCast_ESP8266.ino. Open this .ino file in the Arduino IDE.
• For ESP32: Navigate to and open the ESPTimceCast_ESP32 project folder. Inside, you'll find the main sketch file, typically named ESPTimceCast_ESP32.ino. Open this .ino file in the Arduino IDE.
• Open the Project Folder:For ESP8266: Navigate to and open the ESPTimceCast_ESP8266 project folder. Inside, you'll find the main sketch file, typically named ESPTimceCast_ESP8266.ino. Open this .ino file in the Arduino IDE.For ESP32: Navigate to and open the ESPTimceCast_ESP32 project folder. Inside, you'll find the main sketch file, typically named ESPTimceCast_ESP32.ino. Open this .ino file in the Arduino IDE.

Upload the Sketch:

• With the main sketch file open, click the "Upload" button (the right arrow icon) in the Arduino IDE toolbar. This will compile the entire project and upload it to your board.
• Upload the Sketch:With the main sketch file open, click the "Upload" button (the right arrow icon) in the Arduino IDE toolbar. This will compile the entire project and upload it to your board.

Upload /data folder (LittleFS):

• This project uses LittleFS for storing web interface files and other assets. You'll need the LittleFS Uploader plugin.
• Install the LittleFS Uploader Plugin
• Before uploading, ensure the Serial Monitor is closed.
• Open the Command Palette (Ctrl+Shift+P on Windows, Cmd+Shift+P on macOS).
• Search for and run: Upload Little FS to Pico/ESP8266/ESP32 (the exact command name might vary).
• Important for ESP32: If the upload fails, you might need to manually put your ESP32 into "Download Mode." While holding down the Boot button (often labeled 'BOOT' or 'IO0' or 'IO9'), briefly press and release the RST button, then release the Boot button.
• Upload /data folder (LittleFS):This project uses LittleFS for storing web interface files and other assets. You'll need the LittleFS Uploader plugin.Install the LittleFS Uploader PluginBefore uploading, ensure the Serial Monitor is closed.Open the Command Palette (Ctrl+Shift+P on Windows, Cmd+Shift+P on macOS).Search for and run: Upload Little FS to Pico/ESP8266/ESP32 (the exact command name might vary).Important for ESP32: If the upload fails, you might need to manually put your ESP32 into "Download Mode." While holding down the Boot button (often labeled 'BOOT' or 'IO0' or 'IO9'), briefly press and release the RST button, then release the Boot button.

Display Behavior

ESPTimeCast automatically switches between two display modes: Clock and Weather. If "Show Weather Description" is enabled a third mode (Description) will display with a duration of 3 seconds, if the description is too long to fit on the display the description will scroll from right to left once.

What you see on the LED matrix depends on whether the device has successfully fetched the current time (via NTP) and weather (via OpenWeatherMap).The following table summarizes what will appear on the display in each scenario:

How it works:

• The display automatically alternates between Clock and Weather modes (the duration for each is configurable).
• If "Show Weather Description" is enabled a third mode Description will display after the Weather display with a duration of 3 seconds.
• In Clock mode, if NTP time is available, you’ll see the current time plus a unique day-of-week icon. If NTP is not available, you'll see ! NTP.
• In Weather mode, if weather is available, you’ll see the temperature (like 23ºC). If weather is not available but time is, it falls back to showing the clock. If neither is available, you’ll see ! TEMP.
• All status/error messages (! NTP, ! TEMP) are big icons shown on the display.