I²C boards for machines that run on real batteries.
Hot-swap power, servo drive and sensing on one 4-pin bus. Works with Qwiic and PiicoDev. Designed in Australia.
Each board fixes one problem that turns up when a machine runs on batteries. Each has its own site with the full technical detail: specifications, connectors, addresses and code.
Available 25 October 2026AUD $59
The problemChanging the battery switches the robot off, and the first sign of a flat pack is a machine that has stopped.
Two 5S packs in, one load out, 100 W peak. Pull a pack and the load never notices. Bus voltage, current and power come back over I²C from an INA226, so your code knows when it is time to swap.
Open the Kookabus-01 siteComing 1 November 2026
The problemBus servos need a fast half-duplex serial line that ties up a UART, and on a shared power lead one stalled servo can take the rest down with it.
Drives up to eight ST3215 or other Feetech-protocol bus servos from the same I²C connector. One 12 V XT60 input, a 20 A fuse, and a resettable fuse on every port so one stalled servo never takes down the rest.
Open the Kookabus-02 siteRev 5, in design
The problemA small robot needs 6 to 12 V. A lithium pack needs a charger and care; a bare AA holder has loose wires, no fuse and no way to tell if the cells are flat.
Eight shop AA cells, alkaline or NiMH, switched to 4, 6 or 8 in series and out through an XT60 behind a 3 A resettable fuse. The output blocks reverse current, and a TEST button shows green or red for the cells in use.
Open the Kookabus-03 siteKookabus-01 and Kookabus-02 each carry two 4-pin bus connectors, so boards chain from one to the next and back to your controller. Kookabus-03 is a plain power source with no bus connection.
The connector is the 4-pin JST-SH 1.0 mm used by PiicoDev and Qwiic, with the same pin order, so the boards plug straight into those ecosystems and their cables.
