I2C has always carried an unwritten rule: keep the bus short, a few dozen centimeters at most, or noise and capacitance will corrupt the signal. Arduino's new Modulino Extender sidesteps that limitation with a single chip. Built around the Linear Technology LTC4311 I2C accelerator, the board improves bus rise time and low-state noise margin to carry a standard I2C link up to 30 meters (98.4 feet) of wired distance. It is a purely passive-feeling addition with no driver or library required, and the module ships with two 10 cm QWIIC-to-jumper cables to get started.

Reaching that full range comes with cabling caveats worth noting for anyone wiring up a distributed sensor network. The 30-meter figure only holds at 100 kHz, and Arduino's documentation spells out the tiers: standard QWIIC cables cover runs under a meter, shielded twisted-pair is recommended for 1 to 10 meters, and long hauls of 10 to 30 meters call for Cat5e or Cat6 shielded or foiled twisted pair, routed well away from power lines and other electrical noise. The chip supports up to 400 kHz operation, tolerates a 1.6V to 5.5V supply, and draws roughly 200 microamps.

Alongside it, the Modulino Hub targets the other classic I2C headache: address collisions. Complex builds often stack multiple sensors that share the same default address, and while the protocol theoretically addresses up to 127 devices, real projects hit conflicts fast. The Hub uses a Texas Instruments TCA9548A 8-channel I2C switch to fan a single bus out to eight QWIIC ports, each isolated on its own channel with a 4.7kΩ pull-up. Up to eight Hubs can be daisy-chained, each on its own address between 0x70 and 0x77, for a total of 64 devices. On Linux systems, the TCA9548A is handled by the i2c-mux-pca954x driver in the mainline kernel, which exposes each of the chip's channels as a separate virtual I2C adapter once the device is described in the platform device tree. Both boards measure 41 x 25.36 mm (1.6 x 1.0 inches) and weigh 4.4 grams, and a third new module, the Modulino Motors, drives two DC motors or a single stepper.

The modules are pitched at the Arduino UNO R4 WiFi and the newer Arduino UNO Q, and that second target is the more interesting pairing for anyone tracking Linux on small boards. The UNO Q carries a quad-core Qualcomm Dragonwing QRB2210 running a full Debian desktop alongside an STM32U585 microcontroller, so a QWIIC sensor mesh stitched together with these Hubs and Extenders feeds straight into a Linux userspace where you can log, process, or serve the data locally. That combination turns the I2C plumbing into something closer to a self-contained edge node than a bare microcontroller peripheral chain. Arduino's arduino-modulino-mpy library extends the software options further, supporting any I2C-capable board running MicroPython and making the Modulino ecosystem reachable from Python without the Arduino IDE.

The Modulino Hub sells for $8.85 (€8.84) and the Modulino Extender for $11.93 (€12.33), both available now through Arduino's store. As open source hardware, they slot cleanly into the existing QWIIC ecosystem, so the sensors and actuators you already own should connect without adapters.