nodemcu-firmware/docs/en/modules/cron.md

Cron Module

Since	Origin / Contributor	Maintainer	Source
2016-12-18	PhoeniX	PhoeniX	cron.c

Cron-like scheduler module.

!!! important This module needs RTC time to operate correctly. Do not forget to include the rtctime module and initialize it properly.

!!! important The cron expression has to be in GMT/UTC!

cron.schedule()

Creates a new schedule entry.

Syntax

cron.schedule(mask, callback)

Parameters

• mask - crontab-like string mask for schedule
• callback - callback function(entry) that is executed at the scheduled time

Returns

cron.entry sub module

Example

cron.schedule("* * * * *", function(e)
  print("Every minute")
end)

cron.schedule("*/5 * * * *", function(e)
  print("Every 5 minutes")
end)

cron.schedule("0 */2 * * *", function(e)
  print("Every 2 hours")
end)

cron.reset()

Removes all scheduled entries.

Syntax

cron.reset()

Parameters

none

Returns

nil

cron.entry Module

cron.entry:handler()

Sets a new handler for entry.

Syntax

handler(callback)

Parameters

• callback - callback function(entry) that is executed at the scheduled time

Returns

nil

Example

ent = cron.schedule("* * * * *", function(e)
  print("Every minute")
end)

ent:handler(function(e)
  print("New handler: Every minute")
end)

cron.entry:schedule()

Sets a new schedule mask.

Syntax

schedule(mask)

Parameters

• mask - crontab-like string mask for schedule

Returns

none

Example

ent = cron.schedule("* * * * *", function(e)
  print("Tick")
end)

-- Every 5 minutes is really better!
ent:schedule("*/5 * * * *")

cron.entry:unschedule()

Disables schedule.

Disabled schedules may be enabled again by calling :schedule(mask).

Syntax

unschedule()

Parameters

none

Returns

nil

Example

ent = cron.schedule("* * * * *", function(e)
  print("Tick")
end)

-- We don't need this anymore
ent:unschedule()