Pinout
Qwiic / STEMMA QT connector (4-pin, I2C) pinout
Pins
- 1: GND (black)
- 2: 3.3V (red)
- 3: SDA (blue)
- 4: SCL (yellow)
Specifications
| Contacts | 4 |
|---|---|
| Connector | JST SH, polarized |
| Pitch | 1.0 mm |
| Contact rating | 1 A, 50 V (JST SH) |
| Supply | 3.3 V |
| Bus | I2C only (100 / 400 kHz) |
| Pin order | GND, 3.3 V, SDA, SCL |
| Wire colours | Black, red, blue, yellow |
| Compatible | SparkFun Qwiic and Adafruit STEMMA QT |
Notes
- JST SH 1.0mm, 4-position, polarized — a genuine Qwiic or STEMMA QT part physically cannot be plugged in reversed, and SparkFun's Qwiic and Adafruit's STEMMA QT ecosystems share this exact same connector and pin order, so cables cross freely between them.
- The trap: plenty of non-Qwiic boards use this identical JST-SH 1.0mm 4-pin housing for their own "I2C connector" with a DIFFERENT internal pin order. A cable that physically mates does not guarantee correct wiring — only trust the GND/3V3/SDA/SCL order on parts explicitly marked Qwiic or STEMMA QT compliant.
- I2C only — always 3.3V, always this one bus. There is no variant carrying other signals despite looking identical.
