> ## Documentation Index
> Fetch the complete documentation index at: https://learn.pcbcupid.com/llms.txt
> Use this file to discover all available pages before exploring further.
> The Glink connector on every Glyph board is electrically and mechanically compatible with Qwiic and STEMMA QT for plug-and-play I2C sensor chaining.
# Glink Connector Overview
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.
## 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](https://www.sparkfun.com/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
## Glink Pinout
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](https://shop.pcbcupid.com/product-category/development-boards/), enabling rapid prototyping and seamless integration with a vast ecosystem of compatible sensors and modules.