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What's GLINK?

pcbcupid glink feature image

All Glyph Development boards have a GLINK connector which is compatible with QWIIC / STEMMA QT connector. GLINK offer a solder-free, easy-to-use solution for connecting development boards to various sensors, shields, and accessories. Their polarized connectors eliminate the risk of incorrect wiring, while daisy-chaining capabilities allow multiple devices to be connected efficiently using the I2C bus

GLINK ensure compatibility with a wide range of I2C-based modules and sensors produced by Adafruit & Sparkfun. This standardized approach not only accelerates prototyping but also enhances the overall user experience by eliminating common wiring errors and reducing setup time.

pcbcupid glink connector & cable

Feature​

GLINK connectors provide several key advantages:

  • Solder-free connections for rapid prototyping and experimentation
  • Polarized connectors to prevent incorrect wiring
  • Daisy-chaining capability for connecting multiple devices efficiently
  • Compatibility with the widely-used I2C communication protocol
  • Interoperability with QWIIC and STEMMA QT ecosystems

Standard​

GLINK follows QWIIC standard:

  • JST PH (2mm pitch) Connector
  • Pinout - GND, VCC, SDA & SCL
  • Device connected using GLINK should be 3.3V
  • Max current on a GLINK cable is 226mA
  • Using 28AWG is good for up to 1.4A (recommended not push more than 1.4A)
  • The GLINK cable length can be upto 1M

pcbcupid glink connector

The GLINK connector follows a standardized pinout, identical to Adafruit's STEMMA QT:

  • SCL (Yellow wire)
  • SDA (Blue wire)
  • 3.3V (Red wire)
  • GND (Black wire)

This consistent pinout ensures compatibility across different devices and ecosystems, allowing users to mix and match components from various manufacturers seamlessly.

Technical Information​

Power Lines​

GND : Serves as the common ground reference for both power and data.

3.3V: Provides power to connected devices. While the standard specifies 3.3V, the system can accommodate voltages between 3-5V DC for flexibility with certain high-current devices.

Data Lines​

SDA (Serial Data): Carries the bidirectional data for I2C communication.

SCL (Serial Clock): Provides the clock signal for synchronizing I2C data transfer.

Important Considerations​

  • Voltage Compatibility: While GLINK operates at 3.3V, connected devices must be capable of operating within the 3-5V range. Devices requiring lower voltages must incorporate their own voltage regulators.
  • Pull-up Resistors: I2C devices are expected to include pull-up resistors on the SDA and SCL lines to the positive voltage (3.3V). This is crucial for proper I2C communication.
  • Level Shifting: Connected devices should implement I2C level shifting if operating at different logic levels.
  • Current Limitations: It's crucial to stay within the 226mA limit per GLINK cable to ensure safe and reliable operation or you can decrease your wire gauge to handle current up to 1.4A.
  • Daisy-Chaining: When connecting multiple devices in a daisy-chain configuration, be mindful of the cumulative current draw and potential voltage drop across the chain.

By sticking to these standards and considerations, GLINK provides a robust and flexible connectivity solution for GLYPH development boards, enabling rapid prototyping and seamless integration with a vast ecosystem of compatible sensors and modules.