# Map

Displays an interactive map with either street or satellite overlays, with the latest position of the hardware and optionally the app shown. The position of the device running the app is shown if the *Show my location* widget option is enabled.

### Datastream

Select or create a datastream of [data type](https://docs.blynk.io/en/~/revisions/ynmC8lZ6FPocTYWigjcO/blynk.console/templates/datastreams/datastreams-common-settings/data-type) location or string.

### Widget Controls

The widget controls consist of gestures:

* **Home**:  Click on the arrow at the bottom right of the map to zoom to the latest position.
* **Zoom**: pinch open to zoom out, pinch closed to zoom in.
* **Set North up**: when the map is rotated, a compass icon will be in the upper right of the map. Tap this icon to set the orientation of the map so the North direction is up.
* **Double tap**:  zooms the map in.
* **Drag**:  pans the map.

### How to process widget with the hardware

When button is pressed, 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 Widget is set to Datastream with Virtual Pin V7, you can use such code:

```cpp
BLYNK_WRITE(V7) {   
  // Called when the datastream virtual pin V2 is updated 
  // by Blynk.Console, Blynk.App, or HTTP API. 

  String value = param.asString();
  // Parse value by the "," character to get the coordinates
  String sLat = value.substring(0, value.indexOf(","));
  String sLon = value.substring(value.indexOf(",")+1);
  Serial.print("V7: "); Serial.print(sLat.toDouble(), 6);     Serial.print(", "); Serial.println(sLon.toDouble(), 6);
    
} // BLYNK_WRITE()
```

```
https://{server_address}/external/api/get?token={token}&{pin}
```

#### Changing the datastream value(s)

**Hardware:**

```cpp
double lat = 40.8414;
double lon = -73.8731
Blynk.virtualWrite(V1, lon, lat);
```

**HTTP API:**

```cpp
https://{server_address}/external/api/update/?token={your 32 char token}&V1=-73.8731&V1=40.8414
```

{% hint style="danger" %}
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](https://docs.blynk.io/en/~/revisions/ynmC8lZ6FPocTYWigjcO/blynk-library-firmware-api/blynk-timer).
{% endhint %}

Sketch:[ ](https://github.com/blynkkk/blynk-library/blob/master/examples/GettingStarted/BlynkBlink/BlynkBlink.ino)[WidgetMap](https://github.com/blynkkk/blynk-library/blob/master/examples/Widgets/Map/Map.ino)

### Change Widget Properties

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

```cpp
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

{% hint style="danger" %}
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.
{% endhint %}

### Properties you can change

You can change the properties *label*, *color*, *isDisabled*, *isHidden* of the widget from your hardware, or via an [HTTP API](https://docs.blynk.io/en/~/revisions/ynmC8lZ6FPocTYWigjcO/blynk.cloud). 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**

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

#### **Set Button Color**

```cpp
//#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.

```cpp
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.

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

### Change widget properties via HTTPs API

## Updates the Datastream Property and all assigned Widgets

<mark style="color:blue;">`GET`</mark> `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}<mark style="color:red;">\*</mark> | string | Get from the bottom right of your Blynk console. [More information](https://docs.blynk.io/en/~/revisions/ynmC8lZ6FPocTYWigjcO/blynk.cloud/device-https-api/troubleshooting). |

#### Query Parameters

| Name                                    | Type   | Description                                                                                                                                                     |
| --------------------------------------- | ------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| token<mark style="color:red;">\*</mark> | string | Device [auth token](https://docs.blynk.io/en/~/revisions/ynmC8lZ6FPocTYWigjcO/concepts/device#authtoken) from Device info                                       |
| pin<mark style="color:red;">\*</mark>   | string | The datastream [virtual pin](https://docs.blynk.io/en/~/revisions/ynmC8lZ6FPocTYWigjcO/blynk.console/templates/datastreams/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                                                                                                                                                   |

{% tabs %}
{% tab title="200 Success" %}

```
```

{% endtab %}

{% tab title="400 Could not find a device token" %}

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

{% endtab %}
{% endtabs %}

### **Sync to the latest known state**&#x20;

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](https://docs.blynk.io/en/~/revisions/ynmC8lZ6FPocTYWigjcO/blynk-library-firmware-api/state-syncing) for more details.

```cpp
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()
}
```