Xerantrop

Xerantrop teaches electronics by having you build the circuit. Place parts on a board, wire their terminals together, and a solver works out what the circuit actually does — then the board shows you. THE BENCH A grid you build on. Add parts from the palette by tapping or dragging, move them, inspect them, adjust their values where that makes sense, wire them up or take them off the board. Two explicit modes keep it clean: move mode repositions parts without drawing stray wires, wire mode connects one terminal to another. Placed parts keep their own symbols and values, so a battery, resistor, capacitor, diode, LED, switch or motor stays recognisable, with its voltage, resistance or capacitance printed on it. THE SOLVER It reads the nodes, the branches, the part properties, the sources, the resistance, the current and the continuity — so it knows whether your loop is open or closed, what the readings are, and whether you have created a short. Tap any part or node for its voltage drop and its current in milliamps. The status area reports the board as idle, live, warning or shorted. Energise the circuit and the wires animate the flow, LEDs glow at their calculated brightness and motors turn. The animation can be switched to a static highlight for a calmer board. THE PARTS Nine-volt batteries, AA and coin cells, resistors across a range of values, potentiometers and photoresistors, capacitors, red green and blue LEDs, ordinary diodes, push buttons and toggle switches, NPN and PNP transistors, DC motors, piezo buzzers and multimeter probes. Each has a page explaining what it does, its electrical model, its specifications, its pin layout and the law the solver applies to it — and it can be sent straight to the bench from there. CHALLENGES Tasks with a goal, a set of starting parts, pass conditions, a hint and a note on what it teaches. Conditions are checked by the same solver you build with: a power source present, a closed loop, an LED current inside a target range, a limit on how many parts you may use, a specific voltage or behaviour. Finished circuits are graded up to three stars, and a cleaner solution with fewer parts scores higher. Clearing them unlocks more components. SAVED RIGS Save a circuit and come back to it with its parts, positions, values, switch states and wiring intact. Rigs are sorted by when you last touched them and split between free builds and ones that came from a challenge. Fork one to experiment without losing the original. PROGRESS Stars earned, rigs saved and challenges cleared, plus a record of your cleanest solutions — a reason to reopen a finished challenge and do it in fewer parts without breaking it. WHAT IT DOES NOT DO No account, no server, no connection. Stars, results, unlocked parts, rigs and profile are stored in the app on the device, and progress can be reset from settings. For beginners, students and hobbyists who would rather wire something up than read about it.