This is my dot matrix clock made with ESP8266 WiFi capable MCU. Accurate time signal is acquired from NTP and weather information is available through Openweathermap.org API.

• 24 hour time display
• NTP sync
• Optional weather data from Openweathermap.org API
• Outside temperature display
• Wind speed display
• Wind direction display
• DST support (automatic change)
• Over the Air (OTA) firmware upgrade capability
• WifiManager Soft AP configuration interface

• ESP8266 board (recommended: NodeMCU/compatible see BOM)
• MAX7219 based LED matrix display (order from China)
• Openweathermap account (optional)
• PlatformIO

Current weather is displayed 3 times per minute for 4 seconds.

• NodeMCU v3 board
• MAX7219 based LED matrix
• Micro usb to USB cable
• Female-female dupont cable 5pcs (usually comes with the display)

NodeMCU 3.3V -> Matrix Vcc
NodeMCU GND  -> Matrix GND
NodeMCU D8   -> Matrix DIN
NodeMCU D7   -> Matrix CS
NodeMCU D6   -> Matrix CLK

• Download and install PlatformIO
• Optionally read https://docs.platformio.org/en/latest/quickstart.html

PlatformIO automatically downloads all required libraries, boards, and configures your environment.

Optional steps for weather info functionality

• Openweathermap: http://openweathermap.org/

  • Register an account
  • Get your API key at: https://home.openweathermap.org/api_keys
  • Find your location/city id on here: https://openweathermap.org/find?q=

• Changes in file main.cpp needed for weather functionality

  • Add your api key from openweathermap: uncomment define WEATHERKEY
  • Add your city id from same
  • Save file

PlatformIO serial

platformio run --target upload

PlatformIO OTA

platformio run -t upload --upload-port <IP address of ESP>

• Latest version of the Firmware uses the WifiManager library by tzapu to setup the clock

• If no known WiFi AP is nearby, the clock starts the config portal

• Connect to SSID: "MatrixAP"

• Point your browser to 192.168.4.1

• Follow instructions to configure your SSID, pass, API key and CityID

• To manually force config AP mode, short D5 pin on NodeMCU to ground to enter

Obsolete config instructions for the serial version:

• If the clock fails to connect to an AP it will ask for credentials
• Run serial monitor (Arduino IDE) or minicom/putty, etc at 9600 bps
• Type in your own Wifi credentials

• Dimmable display brightness (request)
• Multiple NTP time-zone support
• bugfix, testing

• Vajk for beta testing & original HOWTO
• William Moeur for NTP code