Numeric Input

Increments or decrements the last datastream value by a configured step value. Only the whole number part of a double data type value will be incremented/decremented. You can also type the number in directly.

Datastream

Select or create a datastream of data type integer or double.

Widget Controls

The widget has the following controls:

• + tap to increase the whole part of the datastream value by the STEP.

• - tap to decrease the whole part of the datastream value by the STEP.

Widget Settings

• STEP - the amount the datastream value is incremented/decremented by.

• Loop values: when enabled, causes the value to loop to the datastream’s assigned min/max value when the min/max is exceeded. When disabled, the datastream value may only be incremented/decremented to the datastream’s min/max value.

How to process widget with the hardware

When the number is entered into the widget input field or +/- tapped, the new value is sent and stored into the Blynk.Cloud. After that it's sent to your device.

Reading the widget value(s)

For example, if the Widget is set to Datastream with Virtual Pin V1, you can use such code:

BLYNK_WRITE(V1) {
// Called when the datastream V1 value changes

// Assign incoming value from pin V1 to a variable
// according to the datastream data type
int pinValue = param.asInt(); 
// double pinValue = param.asDouble();

Serial.print(“V1: “);
Serial.println(pinValue);
}

Changing the datastream value(s)

You can change the value of the datastream assigned to the widget with the hardware or HTTP API.

For a datastream V1 assigned data type of integer or double:

Hardware:

Blynk.virtualWrite(V1, 3.1415);

HTTP API:

https://{server_address}/external/api/update/?token={your 32 char token}&V1=3.1415

Don't put Blynk.virtualWrite()into the void loop() as it can cause a flood of messages and your hardware will be disconnected. Send such updates only when necessary, use flags, or timers.

Sketch: Basic Sketch

Sketch: Set Property

Sketch: VirtualPinWrite

Sketch: VirtualPinRead

Change Widget Properties

You can change certain properties of the Widget from your hardware. For that, use this command:

Blynk.setProperty(vPin, "widgetProperty", "propertyValue"); 

Where:

• vPin is: virtual pin number the widget is assigned to

• widgetProperty: property you want to change

• propertyValue: value of the property you want to change

Don't put Blynk.setProperty()into the void loop() as it can cause a flood of messages and your hardware will be disconnected. Send such updates only when necessary, or use timers.

Properties you can change

You can change the properties label, color, isDisabled, isHidden of the widget from your hardware, or via an HTTP API. The URL must be encoded, so spaces in labels must be replaced with %20, and color hexadecimal values in the HTTP API URL must include the hash # character urlencoded as %23.

Change Widget Label

Blynk.setProperty(V1, "label", "Air temperature");

Set Text Color

//#D3435C - Blynk RED 
Blynk.setProperty(V1, "color", "#D3435C");

Disable/Enable

Widget will be greyed out on UI and users won't be able to tap on it.

Blynk.setProperty(V1, "isDisabled", true);

Show/Hide

Widget will be hidden from dashboard. Design your UI so that it doesn't look weird when there is no widget.

Blynk.setProperty(V1, "isHidden", true);

Change widget properties via HTTPs API

Updates the Datastream Property and all assigned Widgets

GET https://{server_address}/external/api/update/property?token={your 32 char token}&pin={your vPin}&{property}={value}

The endpoint allows you to update the Datastream Property value via GET request. All widgets (both web and mobile) that are assigned to this datastream will inherit this property. The Datastream Property is persistent and will be stored forever until you change it with another value. In order to clear the property you need to clear the device data in device actions menu.

Example: https://blynk.cloud/external/api/update/property?token=GVki9IC70vb3IqvsV0YD3el4y0OpneL1&pin=V2&label=My%20Label

https://blynk.cloud/external/api/update/property?token=GVki9IC70vb3IqvsV0YD3el4y0OpneL1&pin=V1&color=%23D3435C

https://blynk.cloud/external/api/update/property?token=GVki9IC70vb3IqvsV0YD3el4y0OpneL1&pin=V1&isDisabled=true

Path Parameters

Name	Type	Description
{server address}*	string	Get from the bottom right of your Blynk console. More information.

Query Parameters

Name	Type	Description
token*	string	Device auth token from Device info
pin*	string	The datastream virtual pin (should start with "v")
{property}	string	The property of the widget you want to update: label, color, isDisabled, isHidden
label	string	the text used as widget label
color	string	button color hexadecimal, must include the hash # character urlencoded as %23
isDisabled	string	true or false
isHidden	string	true or false

200 Success

400 Could not find a device token

{"error":{"message":"Invalid token."}}

Sync to the latest known state

You can update your hardware to the latest datastream value from Blynk.Cloud after your hardware went offline, and then came online again. Use Blynk.syncVirtual() to update a single virtual pin, or Blynk.syncAll() to update all virtual pins. See State Syncing for more details.

BLYNK_CONNECTED() { 
  // Called when hardware is connected to Blynk.Cloud  

  // get the latest value for V1
  Blynk.syncVirtual(V1); 

  // Request Blynk server to re-send latest values for all pins
  Blynk.syncAll()
}