Graphic LCD Hookup Guide

Contributors: Jimb0

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Hardware Assembly & Hookup

Before we get to uploading code and sending data to the display, let’s take care of the hardware stuff first. That includes assembling the display, and hooking it up to the Arduino.

Assembly

To “assemble” the LCD, you’ll need to solder something to one (or both) of the 8-pin headers. There are plenty of options available here. To make the LCD breadboard-compatible, straight or right-angle male headers can be soldered in.

Headers plugged in example

LCD with strait male headers soldered in, plugged into a mini blue breadboard.

Otherwise, wires or other connectors can be soldered to the display pins.

Hookup

In this example we’ll be connecting the LCD up to an Arduino, but this hookup should be easily adaptable to other development platforms. For the data transmission pins – SCLK and DN(MOSI) – we’ll use the Arduino’s hardware SPI pins, which will help to achieve a faster data transfer. The chip select (SCE), reset (RST), and a data/command (D/C) pins can be connected to any digital I/O pin. Finally, the LED pin should be connected to a PWM-capable Arduino pin, so we can dim the backlight as we please.

Unfortunately, the LCD has a maximum input voltage of 3.6V, so we can’t hook up a standard 5V Arduino straight to it. We need to shift levels. This leads us to a few options for hookup:

Direct Connect

The easiest hookup is to connect the Arduino pins directly to the LCD. To allow for this easy hookup, you’ll need a 3.3V-operating Arduino like the 3.3V/8MHz Pro or 3.3V Pro Mini.

This setup can work for 5V Arduino’s, ignoring the 3.6V limit on the VCC and data lines. We’ve done this. It works. But it may decrease your LCD’s life.

Direct connect fritzing

The data pins are connected as follows:

LCD PinArduino PinNotes
1 - VCC3.3V (VCC)3.3V only (not 5V!)
2 - GNDGND
3 - SCE7Can be any digital pin.
4 - RST6Can be any digital pin.
5 - D/C5Can be any digital pin.
6 - DN(MOSI)11Can’t be moved.
SCLK13Can’t be moved.
LED9Can be any PWM pin. 330Ω resistor in between the pins.

Limiting Resistors

Sticking resistors in-line with the data signals is a cheap, and easy way to add some protection to the 3.3V lines. If you have an Arduino Uno (or similar 5V ‘duino) and some 10kΩ and 1kΩ resistors lying around, try this:

Connect via resistors

The pins are connected the same as in the above example, however each signal has an inline resistor. There are 10kΩ resistors between the SCLK, DN, D/C, and RST pins. A 1kΩ resistor between SCE and pin 7. And the 330Ω resistor remains between pin 9 and the LED pin.

Level Converters

Finally, a third option for hookup is to use actual level converters to switch between 5V and 3.3V. Boards like the Bi-Directional Logic Level Converter and the TXB0104 are perfect for something like this.

Level Shifter Example

Unfortunately, the LCD has five 3.3V signal inputs and the level shifters only have four channels. If you want to keep the circuit to a single shifter, you can permanently tie RST high (through a 10kΩ resistors), and run the other signals through the shifter. You lose remote reset capability, but the rest of the control remains.

Check out the hook up guides for those boards for more help in shifting the signal between Arduino and LCD.


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