GeeekPi 2-Pack I2C 1602 LCD Display Module 16X2 Character Serial Blue Backlight LCD Module for Raspberry Pi Arduino STM32 DIY Maker Project Nanopi BPI Tinker Board Electrical IoT Internet of Things

I am using this for a little project I'm working on. No complaints at all, but here are a couple of things that might be good to know: 1. The LiquidCrystal_I2C library available from within the Arduino app works fine. You don't need any of the variant versions. Just go into the Library Manager and search for LiquidCrystal I2C. The default one by Frank deBrabander works great. The warning "THIS LIBRARY MIGHT NOT BE COMPATIBLE WITH EXISTING SKETCHES" is probably valid, but I had no issues. 2. Be sure to check the pin order on the I2C thing. They are labeled. Don't just trust pictures in tutorials. 3. The device ID on mine was indeed 0x27. Apparently there is at least one other commonly used value possible, 0x3F. I saw nothing on my display initially, so I tried the I2C scanner on Instructables, which confirmed mine was indeed 0x27. Moral of the story? The potentiometer on the back is very important! Once you're sure your device ID is correct, adjust brightness. Very good deal for what it is - 16x2 characters, nice and bright, and only requires 4 pins (2 of which are power and ground).

Utilisé pour divers projets DIY avec Arduino, reste à voir les boitiers et les rendre autonomes avec VCC, bcp utilisés pour différente programmation, semble bien efficace et solide!

I've bought a number of these and only had an issue with one which was fixed by just twisting the tabs that go through the printed circuit board holding the layers together. (one tab didn't get twisted at the factory)

Very inexpensive screens that work well. Easy to connect thanks to the I2C backpack. The adjustable contrast is really nice as well. Works perfectly for my Arduino projects.

If it doesn't work immediately, the LCD address might be "0x3f" or "0x27" so try both. Also try a couple different libraries and check for updates. I was having issues and was tinkering with these... but it just started working. I'd like to advise exactly as to what worked, but I don't know what did the trick.