WiFi LCD Display

WiFi LCD Display Release status: experimental
Description	An ESP8266 powered text based LCD display
Platform	ESP8266
Download	GitHub

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.

Next Steps

• Update documentation with information about backlight control
• Add a clock
  • Using some big number library?
    • BigNums2x2 - Blogpost
    • https://gist.github.com/ronivaldo/5587355
    • https://forum.arduino.cc/t/large-alphanumeric-on-lcd/8946
    • https://github.com/lyovav/CLOCK-LCD-16X2-BIG-FONT-v1.0
• PCB Design
  • Add 3(?) MOSFET outputs for bigger lights?