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.