Horizontal Slider

A value between two bounds, set by dragging the thumb. Brightness, speed, a temperature setpoint — anything that is not on or off but how much.

What it does

As the thumb moves, the slider writes the value to its signal. The range is the signal’s own: the minimum and maximum you set in the signal’s format (device → signal → Format) are the two ends of the track, so a slider on a 0 – 255 signal writes 0 – 255, and one on a 5 – 30 °C setpoint writes degrees. With a step, the thumb snaps to multiples — 0, 5, 10… — instead of every value in between.

When to use it

• A dimmer or a fan — a PWM output from 0 to 255.
• A setpoint — the temperature a thermostat aims for. This is a state: see ISignal below.
• A servo angle — 0 – 180, with a step of 5 for a steady hand.

Set it up

1. Give the signal its range — A slider goes from the signal’s minimum to its maximum, so set them first: tap the device icon, open the signal, and fill in Minimum and Maximum under Format — 0 and 255 for a PWM, say.
2. Place it — Back on the dashboard, tap + and choose Horizontal Slider under Controllers. Twelve columns wide reads best.
3. Wire it to the signal — Tap the slider, open the Data tab, tap + Add a target and pick that signal.
4. Try it — Close the settings, tap ▶, and drag the thumb: the device receives the value as you move.

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

Step

Appearance — how it looks

Title

Display

Colors

States

• Dragging — the value is written as the thumb moves, paced so the device gets a stream, not a flood.
• Released — the last value stays; the slider shows it.
• Device offline — the last position waits in the Cloud; with ISignal and Restore, the device gets it on reconnect.

Arduino device code

The address is all the device knows — I1 here; use the one the app gave your signal. In the sketch, the block receives the value:

IHorizontalSlider(I1, float v) { … };

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 PWM = 5;

IHorizontalSlider(I1, float v) {       // the signal is 0 – 255 in the app
    analogWrite(PWM, (int) v);
};

void setup() {
    Serial.begin(115200);
    pinMode(PWM, 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(I1, float v) runs with exactly the same value as IHorizontalSlider(I1, float v): 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 slider position is a state. Write ISignal(I1, float v) and turn Restore on, and the dimmer comes back at yesterday’s level by itself, phone off. See One block for everything.

Notes

• Declare the signal as Decimal if you want fractions (22.5 °C), Integer for a PWM.
• Keep the block short: set the output and return. The device receives many values while you drag.
• For a value the device must keep across restarts, the block to write is ISignal — see above.

Next

→ Vertical Slider — the same, upright → Joystick — two values in one gesture