Switch

On or off. A relay, a lamp, a pump, a heater. The switch is the widget for a state that stays — and with one setting on the signal, a state the device finds again by itself after a power cut.

What it does

A tap flips it and writes the On value (1) or the Off value (0) to its signal. Unlike a button, a switch is its position: the app shows it on or off, and the device can be asked to hold that position across restarts (Restore after a restart on the signal).

When to use it

• A relay — lamp, pump, fan, heater. The classic.
• Enable / disable something the device does on its own — automatic watering on or off.
• A state you want back after a reboot — see ISignal below.

Set it up

1. Place it — In edit mode, tap + at the bottom of the dashboard and choose Switch under Controllers.
2. Wire it to a signal — Tap the switch, open the Data tab, tap + Add a target and pick an Integer signal on your device — Pump, for example.
3. Check the values — In the same tab, under What each state sends, the switch sends 1 when on and 0 when off. Change them if your device expects something else.
4. Try it — Close the settings, tap ▶, and tap the switch: the device receives 1. Tap again: 0.

Settings

Tap the widget in edit mode: the sheet opens with a live preview at the top, then two tabs — Data for what it reads or writes, Appearance for how it looks.

Data — what it writes

Targets

What each state sends

Appearance — how it looks

Title

On

Off

Display

States

• On — track in the accent colour, knob to the right. Off — grey, knob to the left.
• Set by the device or a rule — the switch follows: if the device writes InstantIoT.write(I3, 1), or a rule sets the signal, the switch moves on the dashboard.
• Device offline — with ISignal and Restore, the position comes back on reconnect.

Arduino device code

The address is all the device knows — I3 here; use the one the app gave your signal. In the sketch, the block receives the position:

ISwitch(I3, bool on) { … };

Complete sketch — Cloud

Paste it into the Arduino IDE, put your Wi-Fi and the token the app gave you, upload.

#include <InstantIoT.h>

const char* WIFI_SSID    = "MyWiFi";
const char* WIFI_PASS    = "MyPassword";
const char* DEVICE_TOKEN = "PASTE_TOKEN_HERE";

const int RELAY = 5;

ISwitch(I3, bool on) {
    digitalWrite(RELAY, on);
};

void setup() {
    Serial.begin(115200);
    pinMode(RELAY, OUTPUT);
    InstantIoT.begin(WiFiLink(WIFI_SSID, WIFI_PASS), Cloud(DEVICE_TOKEN));
}

void loop() {
    InstantIoT.loop();
}

Other connections

The widget block never changes. Only the begin() line says how the device reaches the app:

Direct needs no token: the phone is at the other end of the wire. See Connect for TLS, timeouts and what to do when it does not connect.

ISignal does the same job — and survives a restart. ISignal(I3, bool v) runs with exactly the same value as ISwitch(I3, bool on): the widget block is the readable form, ISignal the generic one, and you can use either. The difference shows when the device reconnects: with Restore after a restart on the signal, the Cloud sends the last value again and only the ISignal block runs — a switch position is the typical state. Write ISignal(I3, bool on) and turn Restore after a restart on: the pump that was running before the power cut is running again when the device comes back, with nobody’s phone open. See One block for everything.

Notes

• Declare the signal as Integer. bool in the block reads 0 as false and anything else as true.
• A rule can flip the same signal at 7 pm — Set a signal — and the switch on the dashboard follows.
• An LED on the same signal shows what the device actually did, if the device writes back.

Next

→ Segmented Switch — more than two positions → LED — to show the state the device reports