ET-D17
IS31FL3731 Matrix Driver
Drive 144 LEDs with 256 brightness levels over I²C
AED 25.00
Out of stockOverview
Drive 144 LEDs with 256 brightness levels over I²C
The ET-D17 is built around the ISSI IS31FL3731 — 144 LEDs (16×9 charlieplex), 8-bit PWM per LED, 8 frame buffers, blink, breath, audio-sync. It connects over I²C 0x74 (0x77 with JP3) and is powered from 2.7–5.5V from Qwiic.
Two Qwiic / STEMMA QT connectors let you chain it with other boards without soldering, and the 2.54 mm header fits a breadboard.
Designed in Dubai by ElectroTrical — the full schematic, BOM and design notes are published below.
Good for
- Custom LED matrices
- Scrolling text and animations
- Music-reactive displays
Key features
What makes it different
Driver
ISSI IS31FL3731: 144 LEDs (16×9 charlieplex), 8-bit PWM per LED, 8 frame buffers, blink, breath, audio-sync
Interface
I2C 0x74 (0x77 with JP3)
Supply
2.7–5.5V from Qwiic
Outputs
CA1–CA9 + CB1–CB16 on 0.1" headers for your own LED matrix or panel
Qwiic / STEMMA QT
Two JST-SH connectors plus a 2.54 mm header — 3.3 V and 5 V hosts.
Open documentation
Schematic, BOM and layout notes published for every board.
Specifications
Technical specifications
| Driver | ISSI IS31FL3731: 144 LEDs (16×9 charlieplex), 8-bit PWM per LED, 8 frame buffers, blink, breath, audio-sync |
|---|---|
| Interface | I2C 0x74 (0x77 with JP3) |
| Supply | 2.7–5.5V from Qwiic |
| Outputs | CA1–CA9 + CB1–CB16 on 0.1" headers for your own LED matrix or panel |
| Size | 35.0 × 25.0 mm |
|---|---|
| Mounting | 4 × M2.5 holes, 2.54 mm from each corner |
| Connectors | 2 × Qwiic / STEMMA QT (JST SH 4-pin) · 7-pin 2.54 mm header |
| Main IC | IS31FL3731-QFLS2-TR (LCSC C191206) |
| Revision | Rev A |
| Libraries | Adafruit IS31FL3731, CircuitPython is31fl3731, Arduino LedControl-style examples |
|---|
| JP1 (default Closed) | Cut to turn off the LED |
|---|---|
| JP2 (default Closed) | Cut to remove the host-side I2C pull-ups |
| JP3 (default Open) | Bridge to tie AD high → I²C 0x77 |
Performance
Capability
Pinout
Pin map and connections
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VIN | Power | Sensor supply = host logic level |
| 2 | GND | Ground | Ground |
| 3 | SCL | I²C | I²C clock |
| 4 | SDA | I²C | I²C data |
| 5 | SDB | Signal | Shutdown, low = off (pulled high) |
| 6 | INTB | Signal | Frame / audio interrupt, open-drain |
| 7 | AUD | Signal | Audio input for music-sync mode (AC-coupled) |
Qwiic / STEMMA QT pins: GND, VIN, SDA, SCL (same on both connectors). I²C pull-ups (10 kΩ) are on the board; cut JP2 to remove them.
Mechanical
Dimensions and what's in the box
In the box
- 1 × ET-D17 IS31FL3731 Matrix Driver (assembled)
- 1 × 7-pin 2.54 mm male header, unsoldered
Getting started
- Plug in a Qwiic / STEMMA QT cable, or solder the header and wire VIN, GND, SDA and SCL
- Libraries: Adafruit IS31FL3731, CircuitPython is31fl3731, Arduino LedControl-style examples
- Run an I²C scanner to confirm the address: 0x74, 0x77
Compare
Which LED driver board?
| IS31FL3731 Matrix Driver (this board)This board | ET-D16 SK9822 10-LED Stick | ET-D18 TM1638 8-Digit + 8-Key Panel | ET-D05 8-LED RGB Stick | |
|---|---|---|---|---|
| What it does | Drive 144 LEDs with 256 brightness levels over I²C | 10 clocked RGB LEDs (APA102-compatible), 3.3/5 V input | 8 digits, 8 LEDs and 8 buttons on three wires | Eight addressable RGB LEDs with a 3.3 V-safe input |
| Interface | I²C 0x74 (0x77 with JP3) | 2-wire clock + data (SPI MOSI + SCK), up to ~15MHz | 3-wire serial STB / CLK / DIO (not I²C) | — |
| Best for | Custom LED matrices | Flicker-free lighting on camera | Front panels for timers and counters | Status bars and level meters |
| Price | 25 AED | 28 AED | 25 AED | 19 AED |
Downloads
Documents and design files
Need a custom version of this board?
Different connector, size or sensor? We design and build custom variants.