data.on
This method schedules a function to be called when a device variable changes on Grandeur.
A variable can be changed by a paired user from an app, dashboard, or any SDKs. All three of these updates would trigger the on-callback, or you can call it the device's data update handler. But updating a device's data variable from the device itself won't trigger its own update handler.
Update is a special type of event and the function that handles it is called an update handler.
| Name | Type | Description |
|---|---|---|
| path | string | Path of the device variable using dot notation |
| callback | Callback | An update handler for the device variable |
Grandeur::Project project;
Grandeur::Project::Device device;
void voltageUpdatedCallback(const char* path, int voltage) {
// When "voltage" update occurs on Grandeur, this function
// writes it to an analog pin.
Serial.println("Voltage update occurred!\n");
analogWrite(voltage, A0);
}
void setup() {
project = grandeur.init(apiKey, token);
device = project.device(deviceID);
device.data().on("voltage", voltageUpdatedCallback);
}
void loop() {
if(WiFiIsConnected) project.loop();
}