Hands-On RTOS with Microcontrollers

Oneshot timers

A oneshot is a timer that fires only one time. These types of timers are common in both hardware and software and come in very handy when a fixed delay is desired. A oneshot timer can be used when you wish to execute a short piece of code after a fixed delay, without blocking the calling code by using vTaskDelay(). To set up a oneshot timer, a timer callback must be specified and a timer created.

The following is an excerpt from mainSoftwareTimers.c:

1. Declare a Timer callback function that can be passed to xTimerCreate(). This callback is executed when the timer fires. Keep in mind that the callback is executed within the timer task, so it needs to be non-blocking!

void oneShotCallBack( TimerHandle_t xTimer );

2. Create a timer. ...