How to use: Pick a part below, click a starting hole/pin, then click an ending hole/pin to place it. Holes in the same breadboard column-half are already electrically connected; a whole rail is one node. Load a guided project and toggle the reference overlay to see the correct wiring, then try to reproduce it yourself. The continuity check below the board flags a direct short between power and ground.
No short circuit detected between power and ground.
Simplified educational model: components are represented as 2-terminal connections (the potentiometer collapses its 3 legs to 2), the continuity check is a rule-based approximation (not SPICE-accurate current/voltage simulation), and the MCU board exposes only 5 representative pins. Real breadboard prototyping requires checking actual component datasheets, current ratings, and polarity.
Practice breadboard wiring without any hardware: place an LED, resistor, pushbutton, potentiometer, and a simplified microcontroller board, then connect them across a virtual breadboard's power rails and terminal strips. Load one of three guided project templates, toggle a dashed reference overlay to see the correct wiring, and run a rule-based continuity/short-circuit check as you build.
The virtual board follows real breadboard topology: the five holes in a column-half (rows A-E or F-J) are one electrical node, the center gap breaks the connection between the two halves of a column, and each power rail (+ or −, top or bottom) is a single node running the full length of the board. Select a part or "Wire" from the toolbar, click a starting hole or MCU pin, then click an ending hole to place the connection — it is drawn as a colored line with a small marker.
The continuity check runs a union-find pass over every placed wire, closed pushbutton, and potentiometer (resistors and LEDs are treated as current-limiting and do not merge nodes) to see whether any power node and ground node end up electrically connected. A direct wire from power to ground is flagged immediately as a short; a longer chain of wires reaching the same result is flagged as a wiring-path short. LEDs wired straight across power and ground with no resistor in the path trigger a separate advisory.
Blink an LED wires a microcontroller's PWM-capable pin through a resistor to an LED and back to ground — the simplest way to verify a board and its output pin work. Read a Button wires a pushbutton with an external pull-down resistor so a digital input pin reads HIGH only while pressed. Dim an LED with a Potentiometer puts a potentiometer in series with a fixed resistor and LED, so turning the knob changes the current (and brightness) with no code involved. Toggle "Show reference overlay" to see the correct wiring as dashed lines on the same canvas you're building on, then try to match it.
Use this before touching real hardware to rehearse a wiring plan, to understand why a beginner circuit needs a series resistor with an LED, or to see concretely what a "short circuit" and a "pull-down resistor" actually look like on a breadboard. It complements the static, image-first Microcontrollers — Illustrated Guide reader by giving you a hands-on canvas instead of narrative pages.
An LED has very low resistance once it turns on, so without a current-limiting resistor in series, it draws far more current than its rated forward current and burns out almost instantly. The simulator flags any LED wired directly across power and ground with no resistor in the path as an advisory warning.
The tool flags two cases: a single wire directly bridging a power rail (or the MCU 5V pin) to a ground rail (or MCU GND) with nothing between them, and a longer chain of wires and closed switches that ends up connecting power to ground with no resistor anywhere in that path.
This is a deliberate simplification to keep the wiring model tractable — a real potentiometer has two outer legs plus a wiper. Here the two placed terminals represent the outer legs acting as a variable resistor; treat the tool as teaching the rheostat wiring concept, not a full 3-terminal voltage-divider model.
No — this is a rule-based continuity/short-circuit checker, not a SPICE-accurate electrical simulation. It tells you whether nodes are connected and flags common wiring mistakes, but it does not compute actual voltages, currents, or LED brightness.
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