Product Overview
The SparkFun QwiicBus EndPoint extends your I2C communication range up to 100 feet over standard Ethernet cables without the need to packetize your data into a different protocol. Running standard I2C sensors over long distances usually results in noisy, corrupted data, especially around motors or heavy machinery. The EndPoint serves as the start and end of the QwiicBus, but you can also add a MidPoint (not included) to add a drop-in I2C connection to your long-distance differential I2C chain wherever you need it.
Simple Differential Signaling
The simplicity of the QwiicBus EndPoint is one of its biggest appeals. Other long-distance I2C methods force you to translate your communication into RS-485 or 1-Wire packets. Instead, this board uses an NXP PCA9615 IC to convert the two default I2C signals into four differential signals (two for SCL and two for SDA). These differential signals are then sent over a standard Ethernet cable via the onboard RJ-45 connector, which can easily reach up to 100 feet while resisting noise and maintaining signal integrity.

Long-Range Qwiic
Because the EndPoint is fully Qwiic-enabled, you can set up a sensor network in your home or run data lines across an autonomous vehicle with no soldering required! You communicate with the sensors exclusively via I2C, just as you normally would. For hardware flexibility, this updated version features:
- Solderless Connections: Dual Qwiic connectors let you plug directly into your microcontroller and sensor ecosystem.
- Breadboard-Friendly: Standard 0.1-inch spaced pins are broken out for users who prefer a traditional setup.
- Unused Ethernet Pairs: Two additional 0.1-inch spaced pins connect to the unused wire pair inside the RJ-45 cable, giving you a free lane to run whatever custom signals or power lines you need alongside your data.
- Flexible Power: Supports multiple power configurations depending on your application, with a 2.3-5.5V range for the I2C supply and a 3-5.5V range for the differential supply.
Whether you need to extend the range of an I2C sensor on an autonomous vehicle plagued with noise from motors or want to create a vast sensor network in your home or office, the QwiicBus EndPoint is a great solution to extend distance and reduce noise susceptibility.

