Vertical Step Slider
The Vertical Step Slider varies the datastream value between the datastream’s min/max values based on the slider’s vertical position, in increments of the step setting. It is similar in the way a rotary encoder is used to vary an output based on its position.
Select or create a datastream of data type integer or double. Widget properties (label, color, etc.) are also changed via the datastream, but only for virtual, enumerable, and location pins, not digital and analog pins.
The widget has the following controls:
- 1.Step: Defines the minimum increment of values generated in response to movement of the slider by the user. Note that if the hardware, Blynk.Console widget, or HTTP API changes the datastream value, then that change will be reflected in the slider position.
- 2.Send on release: Enable to limit updating the assigned datastream value only when the control is released by the user.
When the control is pressed, value is sent and stored into the Blynk.Cloud. After that it's sent to your device.
For example, if Slider widget is set to Datastream with Virtual Pin V1, you can use such code:
BLYNK_WRITE(V1) // this command is listening when something is written to V1
{
int pinValue = param.asInt(); // assigning incoming value from pin V1 to a variable
if (pinValue == 1){
// do something when the control is pressed;
} else if (pinValue == 0) {
// do something when the control is released;
}
Serial.print("V1 value is: "); // printing value to serial monitor
Serial.println(pinValue);
}
You can update the assigned datastream value using the hardware or HTTP API.
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.
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 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.You can change the properties step, color, label, isDisabled, isHidden, and page of the widget from your hardware, or via an HTTP API. The color hexadecimal values in the HTTP API URL must include the hash # character urlencoded as %23.
Blynk.setProperty(V1, "step", "10");
Set a custom step or datastream value increment/decrement.
Blynk.setProperty(V1, "label", "Status");
Blynk.setProperty(V1, "isHidden", true);
Widget will be hidden from dashboard. Design your UI so that it doesn't look weird when there is no widget.
Blynk.setProperty(V1, "isDisabled", true);
Widget will be greyed out on UI and users won't be able to tap on it.
Blynk.setProperty(V1, "color", "#73D13D"); // green
Blynk.setProperty(V1, "color", "#ED9D00"); // orange
get
https://{server_address}
/external/api/update/property?token={your 32 char token}&pin={your vPin}&{property}={value}
Updates the Datastream Property and all assigned Widgets
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()
}
Last modified 2mo ago