Slide switch

A contact that stays where you leave it — on/off state, read like a button.

Parts in the example:

Switch
LED

The Switch block as it appears on the canvas.

What it is

A slide switch is the button's steady cousin: it has two positions and keeps the last one. Electrically it is the same contact between a GPIO and ground, read with the internal pull-up.

In the simulator

The block shows the slider; click it to toggle. Its position is part of the project — it is saved and comes back when the project is opened, like the position of a real switch on a board.

Pins

Pin	What it is
S	signal — to a GPIO configured as an input
GND	the other side of the contact — to a GND symbol

Wiring

Build this circuit yourself: start a New project, add the parts from the catalog and wire them as in the table.

Switch pin	Goes to
S	D4 on the board (GPIO 4)
GND	a GND symbol

Settings

Double-click the block's title bar to open its card, then the Settings tab. Changes apply to the running simulation right away.

Setting	Accepts	Default	Notes
Contact	Normally open (NA) · Normally closed (NF)	Normally open (NA)

Code

sketch.cpp

#include <Arduino.h>

// A slide switch has a STATE: it stays where you left it. With the contact
// wired to GND and the internal pull-up on, the pin reads LOW while the
// switch is closed and HIGH while it is open.
const int SWITCH = 4;
const int LED = 2;

void setup() {
  Serial.begin(115200);
  pinMode(SWITCH, INPUT_PULLUP);
  pinMode(LED, OUTPUT);
}

void loop() {
  bool closed = digitalRead(SWITCH) == LOW;
  digitalWrite(LED, closed ? HIGH : LOW);
  Serial.println(closed ? "switch closed - LED on" : "switch open - LED off");
  delay(500);
}

Identical to the button: INPUT_PULLUP and digitalRead() == LOW for closed. The sketch copies the state to an LED and prints it twice a second.

Run it

Press Build and run. The first build of a project takes a while; after that, only what changed is rebuilt.

The simulation running: the canvas reacts and the serial monitor shows what the code prints.

Click the switch: the LED follows and the serial monitor changes from “switch open” to “switch closed”. Click again to open it.

How the simulation models it

The block drives the level of its pin: HIGH while open, LOW while closed for a normally-open contact (the Contact setting inverts it).
The state is sent to the simulation at start-up, so a sketch that reads the switch in setup() sees the position it was left in.

Try this

Use the switch as a mode selector: closed, the LED blinks fast; open, it blinks slowly.
Print the state only when it changes, not every half second.