solu3.3v LCD Module for Arduino UNO R3 Mega2560 16 X 2, 1602 White on Blue

It took me a while to get this going, partly because I took a side tour of the circuit on the back side.I'm using Blue Pill STM32F103C8T6 Canduino board. I have the LCD data lines hooked to STM Port A0 through A7. I could have used 4-bit, but there was no point. I have RS tied to GPIO B 7, R/W* tied to GPIO B 6 and Enable tied to GPIO B 5. The port assignments don't really matter though.For the backlight, I tied Kathode to ground and Anode through 150 ohms to 3v. This is wiring I did on the back of the LCD. Then I put a 10k pot between Gnd and 3v with the wiper going to VO. This was also added on the back. Contrast is great. I deliberately set the backlight a bit dimmer than most people would do.Works just like any HD44780 LCD I've used. So happy to have found one that doesn't need 5v or any additional bus pullups or whatnot.I think the ICL7660 charge pump on the back is odd (in that I traced the circuit and it looks incorrect). I assume they need it internally, but at first I thought it was necessary for the contrast voltage Vo. It is not. Hands off. If you want to learn more, just search 1602A J1 J2 J3. In any event, all you need to do is hookup the backlight to 3v and ground (optionally through an additional current limiting resistor like I did), and put a trimpot between Gnd, 3v and then the wiper goes to Vo. Vo ends up being about 1v. I will probably buy more of these.

Doesn't seem to work at 3.3V as stated. The characters are very dim and the back light doesn't work at all. I'm disappointed in that aspect since I wanted to use it with a ESP32. If you want to use this with a 3.3V device then you'll have to use level shifters.

Not a problem. Working fine!

If you are looking at this and know what you are doing, I suggest the somewhat easier model with the serial board and potentiometer built in. This requires less pins on your micro controller. This unit works well and provides really nice contrast.

Great quality fast shipping. Recommended.

A bit of difficulty with contrast and speed but it does deliver.

proper! arrived early.. ordering more.