WIFI LCD Display

An ESP8266 powered text based LCD display. Connects to an MQTT broker. Supports multiple pages (currently 8). Operated with a single button.

Hardware

• ESP8266 (I used a Wemos D1 dev board)
• HD44780 based LCD display - 16x2 in this case, other sizes will need code adjustments.
  • Pin assignment:
    • Reset - GPIO 12
    • Enable - GPIO 13
    • D4 - GPIO 16
    • D5 - GPIO 5
    • D6 - GPIO 4
    • D7 - GPIO 14
• A single button, connected to GPIO 0 (with pullup)

Software

• Copy config.h.sample to config.h and adjust settings
• Flash to ESP using Arduino IDE

Usage

• Message to display immediately: Send text to <MQTT_TOPIC_BASE>/text
• Paging: Send text to <MQTT_TOPIC_BASE>/page/<PAGENAME>/text
  • Page name is limited to 8 characters
  • If a page already exists, it's overwritten
  • If a page does not exist, it's created. If the page buffer is full, the oldest page (in terms of the last update to a page) is overwritten.

ToDo

• Control page order
• Give pages different importance levels