Image Gallery

Displays one or more images specified by a HTTPS URL. You can change the image shown by configuring a datastream of type integer and then changing the datastream value to correspond to the image URL index (beginning at 0). If only one image URL is assigned, then the datastream value is ignored. Make sure to encode the image URL.

Datastream

Select or create a datastream of data type integer.

Widget Controls

The widget has no controls.

How to process widget input on the device

The datastream value displayed is updated whenever the value stored on Blynk.Cloud changes.

Reading the widget value(s)

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(); 
// float pinValue = param.asFloat()
// double pinValue = param.asDouble();
// String pinValue = param.asStr()
// String pinValue = param.asString()
// String pinValue = param.getBuffer()  // raw data from param buffer
// int value = param.getLength()  // raw data from param buffer

if (pinValue == 1){
  // do something when the value is 1
} else if (pinValue == 0) {
  // do something when the value is 0
}

Serial.print("V1 value is: "); // print value to serial monitor
Serial.println(pinValue);
}

Changing the datastream value

You can update the assigned datastream value using the hardware or HTTP API. You can change the image shown by changing the datastream value to correspond to the image URL index (beginning at 0). If only one image URL is assigned, then the datastream value is ignored. Make sure to encode the image URL.

Hardware:

Blynk.virtualWrite(vPin, 1);

HTTP API:

https://{server_address}/external/api/update/?token={your 32 char token}&V0=1

https://{server_address}/external/api/batch/update/?token={your 32 char token}&V0=1

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, 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");

Change Opacity, Scale, Rotation

Blynk.setProperty(V1, "opacity", 50); // 0-100%

Blynk.setProperty(V1, "scale", 30); // 0-100%

Blynk.setProperty(V1, "rotation", 10); //0-360 degrees

Change Images

Change the individual image by its index:

Blynk.setProperty(V1, "url", 1, "https://image1.jpg");

Change a list of URLs for the widget. First image will have index 0, next 1, and so on.

Blynk.setProperty(V1, "urls", "https://image1.jpg", "https://image2.jpg");

Make sure you not exceed the max string size of 255 chars when sending a long list of URLs

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.

Examples: 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&isDisabled=true

https://blynk.cloud/external/api/update/property?token={token}&pin={pin}&url={index}&url={url}

https://blynk.cloud/external/api/update/property?token=GVki9IC70vb3IqvsV0YD3el4y0OpneL1&pin=V1&url=2&url=https://image%202.jpg

https://blynk.cloud/external/api/update/property?token={token}&pin={pin}&urls={url1}&urls={url2}&urls={url3}

https://blynk.cloud/external/api/update/property?token=GVki9IC70vb3IqvsV0YD3el4y0OpneL1&pin=V1&urls=https://image%201.jpg&urls=https://image%202.jpg&urls=https://image%203.jpg

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, isDisabled, isHidden, url, urls
label	string	the text used as widget label
isDisabled	string	true or false
isHidden	string	true or false
url	string	Replace image by its index. Indexes start from 0. URL should be urlencoded
urls	string	Replace the whole set of images with the new set of URLs. The URLs should be urlencoded

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()
}