System Thread

Waiting for the system

Use waitUntil to delay the application indefinitely until the condition is met.

Use waitFor to delay the application only for a period of time or the condition is met.

Makes your application wait until/for something that the system is doing, such as waiting for Wi-Fi to be ready or the Cloud to be connected. Note: that conditions must be a function that takes a void argument function(void) with the () removed, e.g. Particle.connected instead of Particle.connected(). Functions should return 0/false to indicate waiting, or non-zero/true to stop waiting. bool or int are valid return types. If a complex expression is required, a separate function should be created to evaluate that expression.


waitUntil()

waitUntil

// SYNTAX
waitUntil(condition);

// Wait until the Cloud is connected to publish a critical event.
waitUntil(Particle.connected);
Particle.publish("weather", "sunny");

// For Wi-Fi
waitUntil(WiFi.ready);

// For Cellular
waitUntil(Cellular.ready);

To delay the application indefinitely until the condition is met.

Note: waitUntil does not tickle the application watchdog. If the condition you are waiting for is longer than the application watchdog timeout, the device will reset.


waitUntilNot()

waitUntilNot

Since 2.0.0:

// SYNTAX
waitUntilNot(condition);

// EXAMPLE
Particle.disconnect();
waitUntilNot(Particle.connected);
Log.info("disconnected");

To delay the application indefinitely until the condition is not met (value of condition is false)

Note: waitUntilNot does not tickle the application watchdog. If the condition you are waiting for is longer than the application watchdog timeout, the device will reset.


waitFor()

waitFor

// SYNTAX
waitFor(condition, timeout);

// wait up to 10 seconds for the cloud connection to be connected.
if (waitFor(Particle.connected, 10000)) {
    Particle.publish("weather", "sunny");
}

// wait up to 10 seconds for the cloud connection to be disconnected.
// Here we have to add a function to invert the condition.
// In Device OS 2.0.0 and later you can more easily use waitFotNot()
bool notConnected() {
    return !Particle.connected();
}
if (waitFor(notConnected, 10000)) {
    Log.info("not connected");
}

To delay the application only for a period of time or the condition is met.

Note: waitFor does not tickle the application watchdog. If the condition you are waiting for is longer than the application watchdog timeout, the device will reset.


waitForNot()

waitForNot

// SYNTAX
waitForNot(condition, timeout);

// EXAMPLE
if (waitForNot(Particle.connected, 10000)) {
    Log.info("not connected");
}

Since 2.0.0:

To delay the application only for a period of time or the condition is not met (value of condition is false)

Note: waitForNot does not tickle the application watchdog. If the condition you are waiting for is longer than the application watchdog timeout, the device will reset.