AVR-Based Serial Enabled LCDs Hookup Guide

Contributors: QCPete
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Hardware Hookup - Initial

Install Headers

For this tutorial, we are going to try out Serial UART, I2C, and SPI. In order to easily follow along using a breadboard, solder some headers to the connection ports along the side of your screen. Also, solder some headers onto either side of the logic level converter. This will allow us to easily plug these into the breadboard and wire each data line up with jumper wires.

Headers on screen Headers on logic level converter

Note, we are going to use the 16x2 model with RGB backlight during this tutorial. If you are using a different model (RGB text or the 20x4), then the header pin-out and spacing is identical.

Connecting to an Arduino

The TX pin is used for Serial Uploads of new sketches onto your Arduino, and will cause problems for both your Arduino and the LCD. In other words, when you upload new code to your "project" Arduino, it will be confused because the screen is sharing that TX pin. Please only use software serial to control your LCD. For all of the Serial UART examples, we have setup software serial on D7.

For the first set of examples in this tutorial (SERIAL UART), there are three connections you need to make to the LCD: RX, GND, and RAW. For the other communication protocols that we will explore later, you will need to wire up some other lines. Please see the following Fritzing graphic to see how to wire up your connections through a logic level converter.

Fritzing diagram showing how to do basic wiring of Redboard, Logic Level Converter, and LCDscreen