IN Brief:
- The Modulino Hub divides one controller connection across eight independent I²C branches.
- The Modulino Extender supports cable runs of approximately 30 metres at 100kHz.
- Modulino Motors controls two DC motors or one stepper motor within the same ecosystem.
Arduino has expanded its Modulino development ecosystem with boards for multi-branch I²C networks, longer communication runs, and distributed motor control.
The Modulino Hub provides eight additional I²C branches from one controller connection, allowing peripherals with identical fixed addresses to be separated and reducing the capacitive loading placed on any single branch.
Modulino Extender is a hardware signal-conditioning board intended to carry I²C over distances of approximately 30 metres at the platform’s default 100kHz bus speed. Arduino recommends twisted-pair CAT5 or CAT6 cable for longer runs, with one extender positioned at each end.
Actual distance will depend on cable construction, topology, grounding, interference, pull-up configuration, and the number of attached devices. The board operates at the 3.3V signalling level used across the Modulino range and is supplied with leads for connection to conventional development hardware.
Modulino Motors can control either two DC motors or one stepper motor, combining local processing and dual H-bridge drive circuitry on the module. Placing the driver close to the mechanism can shorten higher-current motor wiring and reduce the number of conductors returning to the central controller.
The modules use Qwiic connections and support Arduino-language and MicroPython development. Breakout pins remain available where a prototype requires conventional wiring or later integration with a custom carrier board.
Together, the three boards address problems that emerge when a compact bench prototype is distributed across a machine or test rig. Sensor addresses begin to collide, cable capacitance destabilises the bus, and actuator wiring becomes increasingly difficult to route from one controller.
The Hub separates repeated devices onto independent branches, which can simplify prototypes containing several identical sensors with non-configurable addresses. A defective or unresponsive branch can also be isolated more readily than on a single shared bus containing every peripheral.
Convenient wiring does not remove bus physics
I²C was developed primarily for short communication paths within a board or enclosure. Longer wiring increases capacitance and exposes the clock and data signals to ground differences, radiated noise, connector resistance, and reflections that are negligible across a few centimetres of PCB trace.
An extender increases the useful distance but does not turn I²C into a fieldbus. Cable routing, grounding, shielding, speed, recovery from a stuck line, and behaviour during connection or disconnection must still be tested under the electromagnetic conditions of the final assembly.
Motor placement introduces separate constraints because brushed DC motors can generate substantial electrical noise, particularly during commutation, reversal, and stall. Suppression components, cable routing, local decoupling, supply distribution, and current limiting remain necessary even when the driver module can be connected in a few minutes.
Stall current deserves particular attention because it can be several times higher than the normal running current. The driver, terminals, cable, connectors, and power source must tolerate that condition long enough for the protection system or control software to respond.
The Modulino approach occupies the space between breadboard development and a custom PCB. It allows sensor placement, cable routes, motor behaviour, processor loading, and control software to be explored without committing immediately to a full hardware revision.
Moving from a working prototype into a production product remains a distinct engineering stage. Environmental ratings, EMC, safety, connectors, mounting, thermal behaviour, manufacturing test, component availability, and lifecycle support may require the functions to be transferred into a controlled custom assembly.
Software obligations expand at the same time, particularly when a prototype becomes a connected industrial device. Reproducible builds, software bills of materials, compliance checking, and maintained embedded operating systems are becoming standard parts of long-lived product development, even where the first demonstrator used a comparatively simple software stack.
Distributed nodes also create more failure points than a single compact board. Every connector, cable, branch, and power feed requires a defined response to disconnection, short circuit, incorrect assembly, and partial power loss.
The new modules are most useful while the architecture remains open to change. A designer can alter sensor count, cable length, motor arrangement, or controller placement without waiting for another PCB, and the resulting measurements can inform the eventual production design.
Arduino has therefore extended Modulino beyond clusters of closely connected modules towards larger physical prototypes. The boards reduce the time needed to assemble and revise those systems, while leaving signal integrity, electrical protection, and qualification firmly within the final engineering process.
