Transparent OLED Setup

Introduction

The future is here! You asked and we delivered - our Qwiic Transparent Graphical OLED Breakout allows you to display custom images on a transparent screen using either I²C or SPI connections.

With Qwiic connectors it's quick (ha ha) and easy to get started with your own images. However, we still have broken out 0.1"-spaced pins in case you prefer to use a breadboard. Brilliantly lit in the dark and still visible by daylight, this OLED sports a display area of 128x64 pixels, 128x56 of which are completely transparent. Control of the OLED is based on our new HyperDisplay library.

This hookup guide will show you how to get started drawing objects and characters on your OLED.

Required Materials

To get started, you'll need a microcontroller to, well, control everything.

If the controller you choose doesn't have a built in Qwiic connector, one of the following Qwiic shields that matches your preference of microcontroller is needed:

You will also need a Qwiic cable to connect the shield to your OLED, choose a length that suits your needs.

Hardware Overview

Listed below are some of the operating ranges and characteristics of the Qwiic Micro OLED.

Characteristic	Range
Voltage	1.65V-3.3V
Supply Current	400 mA
I²C Address	0X3C (Default), 0X3D

Graphical Display

The graphical display is where all the fun stuff happens. The glass itself measures 42mm x 27.16mm, with a pixel display that is 35.5 x 18mm. It houses 128x64 pixels, 128x56 of which are transparent.

Graphical Display

Qwiic Connectors

There are two Qwiic connectors on the board such that you can daisy-chain the boards should you choose to do so. If you're unfamiliar with our Qwiic system, head on over to our Qwiic page to see the advantages!

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Qwiic Connectors

GPIO Pins

When you look at the GPIO pins, you'll notice that the labels are different from one side to the other. One side is labeled for I²C, the other side is labeled for SPI.


I²C Labels	SPI Labels

Power LED

This bad boy will light up when the board is powered up correctly.

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Power LED

You can disable the power LED by cutting the LED jumpers on the back of the board.

Power LED Jumpers

JPX Jumpers

The JPX jumpers are used to either change the I²C address or configure the board to use SPI communications. The other two jumpers allow you to disconnect the power LED and to disconnect the I²C pull-up resistors when chaining several Qwiic devices.

Jumper	Function
JP1	Holds the Chip Select line low when closed. Close for I²C, open for SPI
JP2	Selects the address in I²C mode. Closed for 0x30 by default and open for 0x31. Open for SPI mode to release the D/C pin
JP3	Used to select I²C or SPI mode. Close for I²C, open for SPI
JP4	This jumper should be closed for I²C and open for SPI. This connection allows SDA to be bi-directional

JPX Jumpers

I²C Pull-Up Jumper

I²C devices contain open drains so we include resistors on our boards to allow these devices to pull pins high. This becomes a problem if you have a large number of I²C devices chained together. If you plan to daisy chain more than a few Qwiic boards together, you'll need to cut this I²C pull-up jumper.

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I²C PU Jumpers

Hardware Hookup

Now that you know what's available on your breakout board we can check out the options for connecting it to the brains of your project. There are two options to use - either I²C or SPI - and they each have their own advantages and drawbacks. Read on to choose the best option for your setup.

Warning

Reminder! This breakout can only handle up to 3.3V on the pins, so make sure to do some level shifting if you're using a 5V microcontroller.

I²C (Qwiic)

The easiest way to start using the Transparent Graphical OLED is to use a Qwiic Cable along with a Qwiic compatible microcontroller (such as the ESP32 Thing Plus). You can also use the Qwiic Breadboard Cable to attach any I²C capable microcontroller, or take the scenic route and solder in all the I²C wires to the plated-through connections on the board.

So why use I²C? It's easy to connect with the Qwiic system, and you can put up to two of the Transparent Graphical Breakouts on the same bus without using any more microcontroller pins. That simplicity comes at a cost to performance though. The maximum clock speed of the I²C bus is 400 kHz, and there is additional overhead in data transmission to indicate which bytes are data and which are commands. This means that the I²C connection is best for showing static images.

Breakout Pin	Microcontroller Pin Requirements
GND	Ground pin. Connect these so the two devices agree on voltages
3V3	3.3V supply pin, capable of up to 400 mA output
SDA	SDA - the bi-directional data line of your chosen I2C port
SCL	SCL - the clock line of your chosen I2C port
SA0	Optional : change the I2C address of the breakout. Make sure to cut JP2
RST	Optional : reset the breakout to a known state by pulsing this low

SPI

SPI solves the I²C speed problems. With SPI there is a control signal that indicates data or command and the maximum clock speed is 10 MHz -- giving SPI 50x more speed! However, it doesn't have the same conveniences of the polarized Qwiic connector and low pin usage. You'll need to solder to the pins.

SPI Pinout

You can use SPI to connect as many breakouts as you want. For N displays you will need to use at least N + 3 data pins. That's because the MOSI, SCLK, and D/C pins can be shared between displays but each breakout needs its own dedicated Chip Select (CS) pin.

Breakout Pin	Microcontroller Pin Requirements
CS	A GPIO pin, set low when talking to the breakout
D/C	A GPIO pin, indicates if bytes are data or commands
SCLK	The clock output of your chosen SPI port
MOSI	The data output of your chosen SPI port
3V3	3.3V supply pin, capable of up to 400 mA output
GND	Ground pin. Connect these so the two devices agree on voltages

Warning

Make sure to cut jumpers JP1, JP2, JP3, and JP4 when using SPI mode!

Software

The Transparent OLED Breakout (Qwiic) uses the SparkFun QWIIC OLED Arduino Library. The SparkFun Qwiic OLED library Getting Started guide has library setup instructions and usage examples. Additionally, the full library API documentation is available in the SparkFun Qwiic OLED Library API Reference guide.

Resources and Going Further

For more information on the Transparent Graphical OLED Breakout, check out some of the links here: