Pin Out

The DFRobot Gravity Series stands as a premium open-source electronics toolkit, designed to be modular, plug-and-play, and accessible to all. Featuring robust expansion shields, a diverse array of professional-grade functional modules boasting standard interfaces, and comprehensive documentation, the Gravity Series empowers users of any expertise level to effortlessly connect and combine components, bringing their ideas to life or advancing their projects with ease.

The I2C cable used for Gravity (DFRobot) is the same connector used for Grove (Seeed Studio) and Stemma (Adafruit), but however the pin out wiring is not the same. So while you can use the I2C cable, but you cannot mixed and inter-connect Gravity electronic board with the other brands. An adaptor cable is needed to do the signal line conversion.

Gravity I2C connector details

Gravity I2C inter-connection system uses PH series from JST. JST specialises in connector product. The following is the datasheet and drawing for the JST PH series connectors use.

• Datasheet, JST PH 2.0mm pitch connector (pdf 1.0MB)

Cable Plug

Housing part number: PHR-4
– Available from Digikey: 455-1164-ND

Crimp Pin part number: SPH-002T
– Available from Digikey: 455-1127

Board Socket

– Socket part number: B4B-PH-K-S (Available from Digikey: 455-1706-ND)
– Socket part number: S4B-PH-K-S (Available from Digikey: 455-1721-ND)

Tools Accessories

• Tool hand crimper 28-30AWG side, part number WC-240 (Available from Digikey: 455-1128-ND)
• TOOL EXTRACTION PH SERIES CONTAC, part number EJ-PH (Available from Digikey: 455-EJ-PH-ND)

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Other I2C Connector Standard.

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nodeLynk Introduction

nodeLynk™ – Plug-and-Play I²C Expansion
Simplify your hardware projects with nodeLynk, the universal I²C bus standard from NCD.
Connect sensors, relays, and controllers in seconds—no soldering, no guesswork.

👉 Just plug in. Start building.

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What is nodeLynk?

nodeLynk is a physical I²C expansion standard designed to make prototyping and production easier.

• Uses standard I²C protocol (no special firmware required)
• Built on a 4-pin keyed Molex SL connector
• Supports plug-and-play sensors, relays, and modules
• Chainable – daisy-chain multiple modules with one host controller

Whether you’re using Arduino, Raspberry Pi, Particle, ESP32, or other microcontrollers, nodeLynk lets you skip the breadboard mess and get straight to building.

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nodeLynk Pinout

Every nodeLynk connector has four pins in a fixed order:

• Pin 1 – GND (Ground)
• Pin 2 – VCC (5V)
• Pin 3 – SDA (I²C Serial Data)
• Pin 4 – SCL (I²C Serial Clock)

⚠️ Note: nodeLynk uses 5V I²C. If your controller runs at 3.3V (e.g. Raspberry Pi, ESP32), use a level-shifting adapter.
The pin order is always consistent, so nodeLynk cables work interchangeably across all devices.

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Color code illustration.

Imagine a simple 4-pin connector illustration, left-to-right:

• Brown → GND
• Red → VCC (5V)
• Orange → SDA
• Yellow → SCL

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Why Choose nodeLynk?

• ✅ Plug-and-Play – Skip wiring headaches with standard cables
• ✅ Universal – Works with hundreds of I²C modules
• ✅ Chainable – Add multiple devices on one bus
• ✅ Reliable – Keyed connectors prevent wiring mistakes

nodeLynk I2C connector detail

Cable Plug

Molex plug 50579404 (pdf 0.15MB)

Board Socket

Molex socket 0705530003 (pdf 0.25MB)

nodeLynk Pinout

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Other I2C Connector Standard.

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STEMMA QT is a connector system designed to simplify connecting sensors and other devices to microcontrollers and single-board computers. Used by Adafruit, STEMMA QT aims to streamline the process of prototyping and building electronics projects.

Do note that STEMMA AT, and STEMMA are both the same I2C connection standard, however they are different in size. STEMMA AT is smaller in size (1mm pitch), while STEMMA is easier to handle (2mm pitch).

STEMMA QT connectors typically feature a standardized pinout, making it easy to plug and play with compatible devices. With STEMMA QT, you can quickly connect sensors, displays, actuators, and other peripherals without worrying about wiring configurations or compatibility issues.

One of the key advantages of STEMMA QT is its versatility. It’s compatible with a wide range of microcontrollers and single-board computers, including popular platforms like Arduino, Raspberry Pi, and Adafruit’s own CircuitPython boards. This compatibility makes it a convenient choice for makers and hobbyists working on diverse projects.

Overall, STEMMA QT provides a user-friendly interface for integrating sensors and devices into your electronics projects, allowing you to focus on experimentation and creativity rather than wrestling with wires and connectors. Whether you’re a beginner or an experienced maker, STEMMA QT can help streamline your prototyping process and bring your ideas to life.

The I2C cable connector from STEMMA QT (Adafruit) is compatible to qwIIC (Sparkfun Electronics). Their connector and the pin out are the same.

STEMMA QT I2C connector details

STEMMA QT I2C inter-connection system uses SH/SR series from JST. JST specialises in connector product. The following is the datasheet and drawing for the JST SH SR series connectors use.

• Datasheet, JST SH 1.0mm pitch connector (pdf 1.0MB)

Cable Plug

Housing part number: SHR-04V-S-B
– Available from Digikey: 455-1379-ND

Crimp Pin part number: SSH-003T
– Available from Digikey: 455-1561-2-ND

Board Socket

– Socket part number: BM04B-SRSS-TB (Available from Digikey: 455-BM04B-SRSS-TB)
– Socket part number: SM04B-SRSS-TB (Available from Digikey: 455-SM04B-SRSS-TB)

Tools Accessories

• Tool hand crimper 28-30AWG side, part number YRS-859 (Available from Digikey: 455-2569-N)
• Applic/die set for ind std press, part number CDS SSH/L003-02/CMKS-L (Available from Digikey: 455-CDSSSH/L003-02/CMKS-L-ND)

Check out our best seller general purpose Cable Tester tool.

Other I2C Connector Standard.

You may also be interested in other i2c connector standard available on the market. Click here.