i2c / SPI character LCD backpack

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SKU: ADA292 Brand: Adafruit

LCDs are a fun and easy way to have your microcontroller project talk back to you. LCD backpacks reduce the number of pins needed to connect to an LCD.

$19.65 AUD, inc GST

$17.86 AUD, exc GST

In stock, ships same business day if ordered before 2PM
Delivered by Tue, 26th of Nov

Quantity Discounts:

10-25 $17.15 (exc GST)
25+ $16.61 (exc GST)

Character LCDs are a fun and easy way to have your microcontroller project talk back to you. They are also common, and easy to get, available in tons of colors and sizes. We've written tutorials on using character LCDs with an Arduino (or similar microcontroller) but find that the number of pins necessary to control the LCD can be restrictive, especially with ambitious projects. We wanted to make a 'backpack' (add-on circuit) that would reduce the number of pins without a lot of expense.

By using simple I2C and SPI input/output expanders, we have reduced the number of pins while still making it easy to interface with the LCD. Only 2 pins are needed for I2C, 3 for SPI. For Arduino and CircuitPython/Python users, we provide an easy-to-use library that is backwards compatible with projects using the '6 pin' wiring. This backpack comes with pre-soldered 2-pin and 3-pin terminal block to make a 5-pin terminal for easy wiring.

This backpack will work with any 'standard' character LCD, from 8x1 to 20x4 sizes! As long as they have a 16-pin single-line connection header at the top. We carry a few LCDs that work great. We suggest using our blue & white 20x4 or 16x2 LCDs. Note that it does not work with 16x2 OLED displays.
You can try to connect our RGB 16x2 or 20x4 LCDs, but this backpack will not control the RGB backlight so you'll have to use the backpack only for the 14 digital IO pins (pins #1-14) and connect the backlight pins (#15-#18) directly to your microcontroller with 4 extra wires for color/PWM control as if they were just an RGB LED.

This backpack now comes with a big re-spin that makes lots of improvements:

We've added a 3-5V boost circuit for this backpack to control 5V LCDs even with 3V power and logic.
The contrast potentiometer is much nicer and easier to twist using a small screwdriver.
Added SparkFun qwiic compatible STEMMA QT connectors for the I2C bus so you don't even need to solder the I2C and power lines. Just wire up to your favorite micro using a STEMMA QT adapter cable. QT Cable is not included, but we have a variety in the shop.
Functionality and size/shape are the same - mechanically and code-wise, it is a drop-in replacement.
We've also updated this PCB with Adafruit Pinguin to make a lovely and legible silkscreen.

Advanced users can repurpose the backpack for general-purpose I/O expansion: the MCP23008 has 8 i/o pins (7 are connected) with optional pull-ups, and the SPI 74HC595 has 7 connected outputs.

For a detailed tutorial on usage, including an Arduino library, wiring diagrams, and files, please visit the product page

Technical Details

Revision History:

As of April 17, 2024 - We added pre-soldered terminal blocks.
As of February 8, 2023 - This backpack now comes with a big re-spin that makes lots of improvements:
- We've added a 3-5V boost circuit to use this backpack to control 5V LCDs even with 3V power and logic.
- The contrast potentiometer is a lot nicer and easier to twist using a small screwdriver
- Added SparkFun qwiic compatible STEMMA QT connectors for the I2C bus so you don't even need to solder the I2C and power lines. Just wire up to your favorite micro using a STEMMA QT adapter cable. QT Cable is not included, but we have a variety in the shop.
- Functionality and size/shape are the same - mechanically and code-wise it is a drop-in replacement.
- We've also updated this PCB with Adafruit Pinguin to make a lovely and legible silkscreen.

EagleCAD PCB GitHub files and Fritzing object available in the product tutorial

This board/chip uses I2C 7-bit address between 0x20-0x27, selectable with jumpers
Works with 16x2 and 20x4 Character LCDs
It does not work with 16x2 OLED displays

This product is listed in:

Displays & Screens>Character

Product Comments

Exact shipping can be calculated on the view cart page (no login required).

Products that weigh more than 0.5 KG may cost more than what's shown (for example, test equipment, machines, >500mL liquids, etc).

We deliver Australia-wide with these options (depends on the final destination - you can get a quote on the view cart page):

$3+ for Stamped Mail (typically 10+ business days, not tracked, only available on selected small items)
$7+ for Standard Post (typically 6+ business days, tracked)
$11+ for Express Post (typically 2+ business days, tracked)
Pickup - Free! Only available to customers who live in the Newcastle region (must order online and only pickup after we email to notify you the order is ready). Orders placed after 2PM may not be ready until the following business day.

Non-metro addresses in WA, NT, SA & TAS can take 2+ days in addition to the above information.

Some batteries (such as LiPo) can't be shipped by Air. During checkout, Express Post and International Methods will not be an option if you have that type of battery in your shopping cart.

International Orders - the following rates are for New Zealand and will vary for other countries:

$12+ for Pack and Track (3+ days, tracked)
$16+ for Express International (2-5 days, tracked)

If you order lots of gear, the postage amount will increase based on the weight of your order.

Our physical address (here's a PDF which includes other key business details):

Unit 18, 132 Garden Grove Parade
Adamstown
NSW, 2289
Australia

Take a look at our customer service page if you have other questions such as "do we do purchase orders" (yes!) or "are prices GST inclusive" (yes they are!). We're here to help - get in touch with us to talk shop.

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