GET/POST data to 4x20 LCD display within WLAN
ESP-32 to bridge clients from local WLAN to a HD44780 compatible display
Connected through I2C, needs
GND - GND 5V - 5V G21 - SDA G22 - SCL
greets the browser
Hello from esp32!
use POST with http://esp.your.domain/text/ to control the display.
Available commands:
| parameter | value | explanation │ |
|---|---|---|
| c | clear | clear display, cursor home |
| c | home | cursor home |
| c | blon | backlight on |
| c | bloff | backlight off |
| c | restart | restart the esp32 device |
| t | TEXT | text to be displayed |
| x | 0-19 | cursor x position |
| y | 0-3 | cursor y position |
curl POST example
curl -d "c=clear" -d "t=Some text here" -d "x=0" -d "y=1" -d "t=continue here" -d "x=0" -d "y=2" -d "t=third line" -d "x=0" -d "y=3" -d "t=four" -H "Content-Type: application/x-www-form-urlencoded" -X POST http://esp.your.domain/text/
browser GET example
http://esp.your.domain/text/?c=clear&t=Text%20first%20line&x=0&y=1&t=continue%20second
build
Edit and adjust your ssid and password, compile and upload through the Arduino IDE. Enjoy.