Joystick
This widget allows you to control something in four directions, such as a pair of servos or electric motors.
Mode
For both modes, the joystick will update the datastream(s) with the minimum X to the left, the maximum X to the right, the minimum Y to the bottom, and the maximum Y to the top.
Simple - Assign one datastream each to the X and Y directions of data type integer or double. The output from the joystick movement will vary between the datastream min and max values.
Advanced - Assign one datastream of data type string. In the hardware, you access the X and Y direction values from the datastream. The X and Y values will vary between 0 and 255.
Widget Controls
The widget has one control, the joystick. Press and then slide the joystick radially from the center position to change the X and Y direction outputs.
Settings
The same settings apply to both modes of Simple and Advanced.
Autoreturn - when enabled, the joystick will return to the center position after it is released by the user.
Rotate on tilt - when enabled, the output from the joystick will keep the X and Y directions aligned relative to the smartphone screen orientation (portrait / landscape).
How to process widget input on the hardware
When the joystick is pressed and moved, the value is sent and stored into the Blynk.Cloud. After that it's sent to your hardware.
Reading the widget value
Simple Mode
Advanced Mode
Changing the datastream value(s)
You can also change the datastream value with the hardware, resulting in a change to the widgets assigned to that datastream.
Simple Mode
If V1 and V2 are datastreams of data type integer with the minimum value set to 0 and the maximum set to 255, and V1 is assigned to the joystick X direction, and V2 is assigned to the joystick Y direction, then the following code will move the joystick to the left and upward:
Advanced Mode
If V3 is a datastream of data type string, then the following code will move the joystick to the left and upward position:
Sketch: Joystick
Sketch: Servo
Change Widget Properties
You can change certain properties of the Widget from your hardware. For that, use this command:
Where:
vPin
is: virtual pin number the widget is assigned towidgetProperty
: property you want to changepropertyValue
: 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” and “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.
Set a custom label for the widget
Color
Disable/Enable
Widget will be greyed out on UI and users won't be able to tap on it.
Show/Hide
Widget will be hidden from dashboard. Design your UI so that it doesn't look weird when there is no widget.
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 | string | the text used as widget label |
isDisabled | string | true or false |
isHidden | string | true or false |
color | string | color hexadecimal, must include the hash # character urlencoded as %23 |
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.
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