LED

An LED shows a state your device reports: a door open, a motor running, a tank full. As a Bulb it is simply on or off. As a Solid Dot it dims with the value, from off at MIN to full brightness at MAX.

Try it

The board's code writes TP0. Press and hold the red BUTTON: it sends 1 and the Bulb lights. Switch LED Style to Solid Dot, set MAX to 255 and turn the knob to dim it.

How to add and set up

1. Open the dashboard in edit modeOpen the device and turn on editing. Widgets now show a toolbar and a resize handle.
2. Add an LEDPress + on the right edge of the canvas and pick LED. Drag it into place and resize it with the round handle.
3. Open its settingsClick the gear in the widget's toolbar. The window opens with a Live Preview on the left.
4. Link a Telemetry PointIn Linked Telemetry Points, pick the point your device writes, for example TP0. Check MIN and MAX in Configure TP and press Save TP Settings.
5. Pick a style and colourIn LED Configuration, choose Bulb or Solid Dot. Pick a Widget Color, then press DONE.

The settings window, section by section

Open the window from the widget's toolbar: turn on edit mode and click the gear. On the left is a Live Preview of the tile that blinks the LED once so you see both the on and off look. Nothing changes on the dashboard until you press DONE; CANCEL or ✕ throws the changes away.

1. General Settings

2. Linked Telemetry Points

Pick the point your device's code writes, from TP0 to TP127. A new LED isn't linked to anything, so it stays off until you link it. The pencil opens Configure TP:

These settings belong to the Telemetry Point, so every widget linked to the same point uses the same MIN and MAX.

3. LED Configuration

Bulb: a bulb icon inside the circle, off (grey) or on (filled with the Widget Color). Best for yes/no states. Solid Dot: a plain circle that dims with the value — min = off, max = full brightness. Best for levels, like a PWM output or a light sensor.

4. Widget Color

The colour of the lit LED and of the tile's outline.

What the LED shows for each value

The LED reads the linked Telemetry Point and compares it with that point's MIN and MAX.

Send data from your device

The LED shows the value your board writes with SME.publish(), on the same point you linked on the dashboard. The examples use TP0.

SME.publish(TP0, 1);   // LED on  (MAX)
SME.publish(TP0, 0);   // LED off (MIN)

int state = (digitalRead(BUTTON_PIN) == LOW) ? 1 : 0;   // pressed = 1

if (state != lastState) {     // only when it changes
  SME.publish(TP0, state);
  lastState = state;
}

int level = map(analogRead(A0), 0, 1023, 0, 255);   // 0 to 255

SME.publish(TP0, level);   // 128 = about half brightness

SME_LISTEN(TP0)               // the Switch writes TP0
{
  int on = data.toInt();
  digitalWrite(2, on);        // switch the relay or lamp
  SME.publish(TP1, on);       // the LED on TP1 shows the result
}

#define DASHBOARD_ID     "PROJ-XXXXXXXX"
#define DEVICE_TOKEN     "SME-XXXX-XXXX-XXXX"
#define FIRMWARE_VERSION "1.0.0"
#define WIFI_SSID        "your_wifi"
#define WIFI_PASS        "your_pass"

#include <SMEIoT.h>

#define BUTTON_PIN 4

int lastState = -1;

void setup()
{
  Serial.begin(115200);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  SME.begin(DASHBOARD_ID, DEVICE_TOKEN, FIRMWARE_VERSION,
            WIFI_SSID, WIFI_PASS);
}

void loop()
{
  SME.run();                    // keeps the link alive

  int state = (digitalRead(BUTTON_PIN) == LOW) ? 1 : 0;   // pressed = 1
  if (state != lastState) {     // only when it changes
    SME.publish(TP0, state);    // LED on TP0
    lastState = state;
  }
}

These are snippets. Your sketch also needs #include <SMEIoT.h>, SME.begin(...) in setup() and SME.run() in loop(). The full sketch tab shows a complete example; see the SDK quick start for more.

Move, resize and the widget toolbar

Turn on edit mode to change the layout. Each widget then shows a small toolbar at its top-right:

On a small tile the toolbar folds into a ⋮ menu with the same actions; inside a Container it also has Remove from Container. Move: drag the tile. Resize: drag the round handle at the bottom-right corner — the circle grows with the tile.

Troubleshooting

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