Ref::Timers and Alarms

Alarms (timers) are used for waiting for a certain time. There are also features available for measuring time since the reboot of the system.

Location

• mos/include/alarms.h
• mos/include/timing.h

Functions

Setting Alarms

• Timer callback function signature

    typedef void (*AlarmCallback)(void *);
  

• Initialize an alarm callback

    void alarmInit(Alarm_t *alarm, AlarmCallback cb, void *param)
  

• Schedule an alarm timer for N milliseconds after which the timer will fire (relative value). If the alarm is already scheduled, the function removes it first.

    void alarmSchedule(Alarm_t *alarm, uint32_t milliseconds);
  

• Remove an alarm timer

    void alarmRemove(Alarm_t *alarm);
  

• Get the milliseconds (relative value) after which the alarm is going to fire. Valid only when the alarm is active (i.e. scheduled)

    uint32_t getAlarmTime(Alarm_t *)
  

Getting time

• Getting time elapsed since system start

    ticks_t getJiffies()
    uint32_t getTimeMs()
    uint64_t getTimeMs64()
    uint32_t getTimeSec()
  

• Convert time values

    uint16_t convertAlarmTimerToMs(uint16_t ticks)
    uint16_t convertMsToAlarmTimer(uint16_t ms)
    uint16_t convertSleepTimerToMs(uint16_t ticks)
    uint16_t convertMsToSleepTimer(uint16_t ms)
  

• Get the network-wide synchronized time in milliseconds or seconds

    uint32_t getSyncTimeMs()
    uint64_t getSyncTimeMs64()
    uint32_t getSyncTimeSec()
  

Example

The example code using alarms and timers is available here: apps/tests/AlarmTest