Qwiic / STEMMA QT Pinout
The keyed 4-pin JST-SH I2C connector standard (SparkFun Qwiic / Adafruit STEMMA QT).
Overview
Qwiic (SparkFun) and STEMMA QT (Adafruit) are the same keyed 4-pin, 1.0 mm-pitch JST-SH connector for chaining 3.3 V I2C devices without soldering. The polarized housing cannot be inserted backwards.
The fixed pin order is GND, 3.3 V, SDA, SCL with a standard wire color scheme (black/red/blue/yellow). The two ecosystems are fully cross-compatible.
Pinout
| Pin | Name | Function | Description |
|---|---|---|---|
| 1 | GND | GND | Ground (black wire) |
| 2 | 3.3V | POWER / VIDEO | Power, 3.3 V only (red wire) |
| 3 | SDA | I2C / VIDEO / DATA | I2C data (blue wire) |
| 4 | SCL | I2C / CLK | I2C clock (yellow wire) |
Notes
- Power is 3.3 V by design - this is an I2C-only standard.
- Don't confuse STEMMA QT (JST-SH 1.0 mm) with the larger STEMMA (JST-PH 2.0 mm).
Reference: SparkFun Qwiic / Adafruit STEMMA QT specification· verified 2026-06-27