Kit and build
Say which boxes you own, pick a hub, and plug parts into its ports. The planner checks every port against the connector family and the parts you actually have, then shows what your kits can build.
Ports
Drive geometry
What this build can do
Possible combinations
Each chassis type against each hub you own, counting only parts from that hub's connector family. Layouts counts the distinct ways to place the parts in the ports.
Simulate
A top-down rehearsal of the current build: same ports, same wheel size, same sensors. Use it to tune values before the robot is in your hands, not as a promise of how the real one behaves.
Rule table
Checked top to bottom on every tick; the first rule that matches drives the motors. Hold keeps a rule running for that many milliseconds once it fires. Speeds are percent of top speed.
Goal and decider
Every half second, code turns the sensor numbers into plain facts and asks which mode fits the goal. In the browser a local stand-in answers, because a TypeSafe key must never sit in a web page. The request shown beside the arena is what the bridge sends to Jev.
Below this confidence the robot keeps its current mode instead of switching. Low values flip-flop, high values commit late.
Projects
Eighteen projects in five levels, from one spinning motor to a robot that asks Jev what to do next. Each one is marked against your kits; the ones with a simulator setup load straight into the arena.
Models and ideas
Builds other people have published with instructions, so you can replicate them instead of starting from a pile of beams, and ideas that go past the box. Each model names its kit, its programming path, and what you would need beyond the box. Links go to the source; nothing is copied here.
Paths and hardware
How to program each hub today, what to buy for each path, and where an AI decision layer fits without getting in the way of the motors.
Export code
The current build and brain as Pybricks MicroPython. Rules export as a loop on the hub. Modes export as a hub program that reports facts, plus a laptop bridge that asks Jev and sends back a mode.
Link to the hub
Connect to a Robot Inventor Hub running Pybricks from this page, over Bluetooth LE. Watch what it senses, switch its mode, drive it by hand, or let the stand-in decider pick. Try it on the virtual hub first: that is the simulator answering exactly as the exported program would.
What the hub reports
Drive by hand
Click the pad, then hold an arrow key or W A S D. Letting go stops. Each press is one byte to the hub.
Mode
Hub output
Experimental: send the exported program through the REPL
Pybricks Code compiles a program before sending it; this page cannot, so it starts the hub's REPL and pastes the source line by line, pacing on the echo. Written from the Pybricks profile and MicroPython's paste mode, not yet tried on a real hub. If it fails, the Hub output above says how, and Pybricks Code remains the reliable way.
How a real hub gets here
- Flash Pybricks on the Inventor Hub from code.pybricks.com (Chrome or Edge; it can restore the LEGO firmware later).
- On Export code, pick the modes brain and copy the hub program. Paste it into Pybricks Code and run it once, so the hub keeps it.
- Pick Bluetooth hub here, Connect, choose the hub in the browser dialog, then Start program. If the hub is missing from the dialog, disconnect Pybricks Code first: firmware before 4.0 holds one connection.
- For Jev instead of the stand-in, run
bridge.pyfrom the Export tab on a laptop with your key; the page cannot call Jev.
The EV3 brick has no Bluetooth LE, so this tab cannot reach it. Its modes program picks modes with the brick buttons instead.