Product Overview
Standard I2C communication quickly fails over long distances due to noise and signal drop, which can be incredibly frustrating when wiring a large sensor network or an autonomous robot. The SparkFun QwiicBus Kit solves that problem out of the box by letting you run I2C signals over standard Ethernet cables! Inside this, kit you'll find two EndPoints to start and finish your chain, one MidPoint to drop a sensor in the middle, and two 3-foot Ethernet cables to connect each board to the others.
Differential Signaling & Drop-In Expansion
The QwiicBus system's secret is the NXP PCA9615 IC, which converts standard I2C signals into four differential signals (two for SCL and two for SDA). This allows your data to travel cleanly over long Ethernet cables without requiring you to packetize the communication into complex protocols like RS-485 or 1-Wire packets. You just plug everything in and write your code exactly as you normally would. These differential signals are then sent over a standard Ethernet cable via the onboard RJ-45 connectors, 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! And just to make sure your data survives the journey, the QwiicBus system is built for reliability:
- Massive Range: Differential signaling lets your native I2C signals reach up to 100 feet while maintaining clear signal integrity.
- Proven Performance: In our extreme stress tests utilizing two EndPoints and four MidPoints, all eight connected Qwiic devices operated successfully with almost zero signal loss.
- Expandable Architecture: The EndPoints serve as the start and end of your bus, while the MidPoint lets you easily add I2C sensor connections wherever you need them along the cable run.
- High-Power Delivery: The included MidPoint features a built-in LMR33630 buck regulator that can source high current to power heavy-duty devices attached mid-network.
Whether you have a robot with multiple I2C devices throughout it, a sensor network project with multiple sensors over a large area, or other I2C projects you can think of that require a wired signal transmission over long distances, QwiicBus makes that communication a breeze!


