I²C OLED Backpack Board for EastRising OLED Display

Description

This project is a backpack board that sits on the back of BuyDisplay.com OLED character displays (16×2), and it interfaces the display to the I²C bus for easy connection to many microcontrollers. A software library is available that works with Arduino, Particle and Raspberry Pi boards.

OLEDs are my favorites types of displays because they are bright, easy to read in moderate sunlight, and relatively low in power consumption. I found this wonderful two line by 16 characters OLED display (made by East Rising Technology) from the Chinese company BuyDisplay.com at the very reasonable price of $15. I have ordered from them several times, and they ship very promptly. Additionally, I saw a few vendors on eBay that are re-selling the display at higher price, so you may be able to pick one up there.

This OLED uses the US2066 controller chip which has I²C built in, but there isn’t a simple way to connect to this display with I²C. This project consists of a board that sits on the back of the display, and provides two Qwiic type I²C connectors for easy connection to a microcontroller. This board also has the I²C pullup resistors (enabled with solder jumpers) and a jumper to select the I²C address. NOTE: The display operates on 3.3 volts.

I²C Oled Backpack “bare” pc boards are available from OSH Park.

To make it easy to use this display, I wrote software libraries for the Arduino, Particle and Raspberry Pi microcontrollers. In this library there are over 20 functions, such as clear(), moveCursor(), createChar() (for making custom characters), and write() (for using the Print function).

Files

The schematic and pcb layout files (Eagle and pdf) are available at this Github repository.

Parts

This project does not require many parts, and most are available from Mouser. Bare PC Boards are available from OSH Park.

Qty	Part	Value	Package	Vendor	Part Number
1	C1	.1uF	0805	Mouser.com	80-C0805C104M5R
1	C2	10uF	0805	Mouser.com	647-F921A106MPA
2	J1,J2	4 pin	smd Qwiic connector	mouser.com	485-4208
1	J3	15 pins	.1 Header Pins	Mouser.com	855-M20-9991645
2	R1,R2	4.75K	0805	Mouser.com	71-CRCW0805-4.75K-E3
2	R3,R4	10K	0805	Mouser.com	71-CRCW0805-10K-E3
1	PC Board			OSH Park	Order Link

You can purchase the East Rising OLED display from BuyDisplay.com. It may also be available on eBay.

I²C Oled Backpack “bare” pc boards are available from OSH Park.

Assembly

As you probably noticed, this board uses surface mount components, so you will need some skill in dealing with these small parts. Sparkfun has an excellent series of tutorials if you want to brush up your knowledge on soldering these small parts..

Hookup

NOTE: You will need to make one change to the back of the East Rising OLED module. In order to configure it to work with I²C, you need to move the “BS2 zero ohm resistor” so that it connects with the center pad and the GND pad.

Solder the backpack board to the OLED display module using a 15 pin strip header (.1 inch pin spacing).

Using a 4 pin Qwiic type cable, attach the backpack board to a microcontroller that has a I²C Qwicc type connector on it. This will power the display and connect the SDA and SCL lines to the microcontroller.

NOTE: This display operates on 3.3 volts.

Jumpers

There are three solder jumpers near the center of the backpack board. To “close” a jumper, carefully solder a bridge across the two pads using a small amount of solder.

If you solder across SJ1 and SJ2 you can enable pull up resistors on the signals SCL and SDA (respectively). At least one pull up resistor is required on these lines somewhere on your various hardware boards.

SJ3 is used to set the I²C address of the board.
* If SJ3 is closed (shorted) the address is 3C hex.
* If SJ3 is open (unshorted) the address is 3D hex.

Software

For Arduino, Particle and Raspberry Pi users, the I2cCharDisplay library provides functions the take advantage of the features of this display. An included demo program shows the usage of the functions. These links give the details.

Miscellaneous

Qwiic cables in various lengths are available from Adafruit, Sparkfun, Mouser, Digikey and Amazon.

License Information

Our License Information is here.