GeeekPi IIC I2C TWI Serial LCD 2004 20x4 Display Module with I2C Interface Adapter Blue Backlight for Raspberry Pi Arduino STM32 DIY Maker Project BPI Tinker Board Electrical IoT Internet of Things

It works great for the price, and I would reccomend to others. But, it doesn't have any directions included in the box, so I had to do some research on the I2C and get guided on how to make it work.

This inexpensive display provided a bright, easy to read user interface for my Arduino projects. The 4 wire I2C interface saves a number of output pins on the Arduino. I was able to create a custom character for the degree symbol. I bought the 2-pack and gave the other one to my 13 year old grandaughter for the Arduino I gave her for Christmas. She enjoyed a summer coding camp and is having fun doing experiments.

Very nice. The characters appear silver or white on a blue background. Be aware that the vertical viewing angle of this display (as when viewed either above or below) is extremely narrow. In order to see clear, well defined characters, you pretty much have to look at the display directly from the front. HINT: You can control display brightness using the following simple hack. Remove jumper J3 on the I2C control board. Solder a wire supplying 0-5v DC (a variable PWM voltage from an Arduino for example) to the lower end of SMD resistor R8 on the main board. Cut the trace on the main board feeding SMD resistor R8. See attached photo.

Works well, as advertised. Driven by Raspberry Pi. Easy to install and drive with example Python reference driver. Not impressed with code in driver, but it's open source and easily upgraded.

A good white on blue 4x20 readout. I ordered a 2 pack and received 2 readouts and 2 I2C cables. I’m very happy.

A very useful display for Arduino, Teensy, Seeeduino, Raspberry Pi and other micro controllers. It comes with a piggy back board providing an I2C interface requiring only two data lines to control it. There's a screwdriver adjust for contrast and a jumper for the backlight. The two-pack comes at an excellent price.

Excellent, followed instructions and had sample sketch running on my Arduino Mega in 5 minutes.

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