IS31FL3731 - I2C LED matrix controler, 16x9 CharliePlexing, PWM, Qwiic/StemmaQT

Controling a LED matrix with an I2C CharliePlexing controler

The IS31FL3731 is a CharliePlexing LED controler. The CharliePlexing is a pulse controling method allowing to light up many different LEDs a very short time each one and rely on the retinal persistence to make it appearing as continuously lit.

Thanks to this CharliePlexing controler, you can control an array of 9 x 16 LEDs (144 LEDs) as it was a graphical display panel all via the I2C bus. 
LED Matrix can offert a great look to a project, even better, the IS31FL3731 can control each LED with PWM signal! This means that individual LED intensity can also be controlled. Individual LED intensity over a 16x9 grid would allow beautiful LED lighting effects.
Just send I2C instruction to tell the chip which LED to lit (and brightness) and the chip will take care of it for you.

Even better, the IS31FL3731 CharliePlexing controler has enough memory to store 8 separate frames to be displayed. This feature can be used to created small animation by flipping frames to be displayed with a single command.

This breakout board can use with 2.7 to 5.5V power and logic microcontrolers. You can set the I2C address on the breakout, so you can have up to 4 LED matrices on a I2C bus so up to 4x(9x16)=576 LEDs. Organize them in matrix of Height=9 x wide=64 LEDs --OR-- Height=36 x wide=16 LEDs.

This IS31FL3731 breakout board is great to create small LED displays, use the ready-to-go red, yellow, green, blue, white LED matrix or create your own ones.

The IS31FL3731 breakout is fitted with StemmaQT/Qwiic I2C connector for fast connexion between the breakouts and the controler board (if it has StemmaQt/Qwiic connector), otherwise you can use usual breakout pads or a jst-sh4 to male adapter. StemmaQt/Qwiic allows you to make solderless connections between your development board and the IS31FL3731 or to chain it with a wide range of other sensors and accessories using that connector. As the IS31FL3731 is compatible with 3-5V power and logic, you can use it with your favorite microcontroller or microcomputer board!

To use this product, you will need an additional LED matrix (a pre-assembled one or your own created one ). You'll need to do some basic soldering to attach the driver backpack to a LED matrix and run wires to your microcontroller (or using StemmaQt/Qwiic connector). Soldering the IS31FL3731 breakout board in sandwich with the LED matrix is not too hard (they have been designed for this).

Adadfruit offers support and libraries for Arduino and CircuitPython. MCHobby did offer a MicroPython library for the IS31FL3731 chipset.

Technical details

• IS31FL3731 datasheet
• 2.7 to 5.5V
• I2C interface
• 16x9 = 144 LEDs PWMable (dimmable)
• RAM to store 8 frames
• Qwiic / StemmaQT connector
• Size: 43.2 x 28 x 4.7mm
• Weight: 4.4 gr

Content

For each order, you will receive the IS31FL3731 breakout board, you will need an additional LED Matrix (not included) to use this product. You can also find 16x9 LEDs matrix.

The IS31FL3731 breakout board is fully assembled and tested.