a2nr
/
velxio
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

fix(editor): default Blink circuit needs a series 220Ω resistor 

The default canvas (Arduino Uno + LED on pin 13) wired the LED
directly between pin 13 and GND. Two consequences:

  1. Real-world: that's a short across a forward-biased diode,
     blowing the LED in seconds.
  2. Simulator: ngspice can't find a steady-state branch current
     for an unprotected diode (returns NaN / indeterminate), so
     the LED visual never lights up. Only the wokwi-arduino-uno
     element's BUILT-IN LED (rendered internally by the element,
     not via wire+pinManager) was visible.

Fix: insert a 220Ω resistor between pin 13 and the LED anode,
cathode straight to GND. Same circuit every introductory Arduino
book teaches. SPICE converges, LED blinks visually on the canvas.

Reported by a user trying Blink on a fresh /editor visit.
This commit is contained in:
David Montero Crespo 2026-05-17 23:27:40 -03:00
parent 9f4bf39f65
commit 8a6d72aa50
1 changed files with 27 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
frontend/src/store/useSimulatorStore.ts
View File

@ -1888,28 +1888,51 @@ export const useSimulatorStore = create<SimulatorState>((set, get) => {
},
// ── Components ────────────────────────────────────────────────────────
// Default canvas shown on a bare /editor visit: an external LED on
// pin 13 PROTECTED BY A 220Ω SERIES RESISTOR (the canonical Blink
// wiring textbooks teach). Without the resistor the LED is a direct
// short forward-biased between 5V and GND — real hardware blows the
// diode, and the ngspice solver returns an indeterminate / NaN branch
// current so the visual LED never lights up on the canvas either.
components: [
{
id: 'led-builtin',
metadataId: 'led',
x: 350,
x: 380,
y: 100,
properties: { color: 'red' },
},
{
id: 'r-builtin',
metadataId: 'resistor',
x: 240,
y: 130,
properties: { value: '220' },
},
],
wires: [
// Pin 13 → resistor pin 1 (current-limiting side).
{
id: 'wire-builtin-pin13',
start: { componentId: 'arduino-uno', pinName: '13', x: 0, y: 0 },
end: { componentId: 'r-builtin', pinName: '1', x: 0, y: 0 },
waypoints: [],
color: '#22c55e',
},
// Resistor pin 2 → LED anode.
{
id: 'wire-builtin-anode',
start: { componentId: 'arduino-uno', pinName: '13', x: 0, y: 0 },
start: { componentId: 'r-builtin', pinName: '2', x: 0, y: 0 },
end: { componentId: 'led-builtin', pinName: 'A', x: 0, y: 0 },
waypoints: [],
color: '#22c55e',
},
// LED cathode → GND.
{
id: 'wire-builtin-cathode',
start: { componentId: 'arduino-uno', pinName: 'GND.1', x: 0, y: 0 },
end: { componentId: 'led-builtin', pinName: 'C', x: 0, y: 0 },
start: { componentId: 'led-builtin', pinName: 'C', x: 0, y: 0 },
end: { componentId: 'arduino-uno', pinName: 'GND.1', x: 0, y: 0 },
waypoints: [],
color: '#000000',
},