0.96" I2C OLED Display - Serial Backpack Board RS232 Async Interface Driver

Description

Serial BackPack Board for .95" I2C OLED Display Modules
(Backpack Board and header pins ONLY!  OLED display sold separately.)
The OLED Serial Backpack connects to inexpensive 0.96" 128X64 OLED display modules
that have I2C interfaces, and provides a simple async serial interface for adding a text
display to computers and projects.
The backpack emulates a listen-only dumb terminal, displaying characters received over
a single signal wire, and responding to common cursor control and display management
commands. Two font sizes are supported. Large font displays 4 lines of 13 characters, the
small font displays 8 lines of 25 characters.
The async serial interface receives data at a popular 9600,N,8,1 standard. 19200 baud is
also selectable with a control pin, but higher baud rates may not increase the overall
display capability since throughput to the display is limited by the I2C interface on the
OLED display module. The simple interface with the serial sender offloads tasks like
cursor management and display control, allowing the sender to focus on its primary tasks.
A 128 byte input buffer allows bursts of data to be received faster than they can be
displayed, reducing the need for the sending device to wait for or handshake with the
backpack. If the input buffer is fed data faster than it can drive the OLED I2C interface, a
Buffer Full condition will occur. The backpack indicates a full buffer by displaying a reverse
video "F" in the bottom right corner, and by setting J5 pin 3 to 1. Any data received
during the Buffer Full condition is lost.
For cursor control and display management, the backpack responds to commands using
a modified version of the popular "Matrix Orbital" command set. Matrix Orbital commands
all start with a 0xFE followed by one or more bytes. The command set also controls the
state of two General Purpose Output pins, and enables or disables a splash screen that
can appear at power on, with version and baud rate information.
Hardware Information:
The OLED Serial Backpack board connects to I2C OLED display modules based on the
SSD1306 driver chip. The I2C slave address of the OLED board must be 0x78. Do not
connect to other type displays.
The computer or device that drives the serial backpack and OLED display provides +5 volt
power and serial data to the serial backpack. The serial data is standard 9600 or 19200
baud asynchronous format, with +5 volts as the "mark" or resting state, and 0 volts as the
"space" state.
The backpack board can be attached directly to the OLED board with soldered header pins,
with the component side of the backpack circuit board away from the OLED board. The two
boards must be spaced apart at least 1/8", back to back. Before soldering, ensure that no
pins or components on either board will be close to pins or components on the other board.
The two boards can also be connected using pluggable header connectors or soldered
wires, but ensure that each of the 4 signals are connected to the corresponding pins on
both boards. There are OLED boards with other pin orders! Check that your OLED has the
pins in the order VCC GND SCL SDA!
When the serial backpack is soldered directly to the OLED display with 1/8" spacing,
soldering additional pins and wires to the backpack can be more difficult than populating
the connections before mating the backpack to the OLED board.
In the simplest configuration, only three wires are needed to connect the backpack to the
computer or device that drives the display. +5 volts, Ground and RXD are available on
both J1 and J4. The driving computer or device provides operating power and data to the
serial backpack. Other connections supply beeper output, GPO outputs, baud select, etc.
All backpacks and display modules are 100% tested. Detailed technical specs are supplied
with the board and are probably available upon request. Contact seller for information.
Applying reverse polarity power or voltage over 5.25 volts DC will let the smoke out of
both the backpack and OLED boards. The smoke can not be put back in, and boards with
the smoke released are not covered under warranty. Use of the backpack board requires
soldering and electronic skills. Boards that have been molested unskillfully are not
covered under warranty.
Backpacks purchased with an OLED display module are NOT soldered together. Let us
know if you do want them soldered together, but attaching wires and pins to the backpack
may be more difficult later with mounted boards.
Price is for Serial Backpack Board with pin header strip only.  OLED display modules are
available separately.  Price includes shipping in the USA!
Backpack with OLED display is here:  https://www.ebay.com/itm/283770712594
For international orders, please contact us with your country and postal code and we will
make a listing.