Turn off light in 4 hours

[RSV4]

Hi all

Is there an easy way to switch off a light after a fix time without using a lot of resources on the LM?

Best regards

[Pawel]

os.sleep() function? 

it stops execution of current scrpit only, am i right?

[admin]

If you want to turn objects that were on for a certain time, you need a scheduled or a resident script with large sleep time.

Add "AutoOff" tag to all objects that should be turned off after a certain time. The script below will work for both binary on/off and scaled 1-byte objects. Note that each "on" telegram will reset the auto-off timer for each object.

Code:

-- maximum time that object can be on, in seconds
ontime = 4 * 60 * 60

-- current timestamp, in seconds
now = os.time()

-- get all objects with AutoOff tag
objects = grp.tag('AutoOff')

-- check all objects
for _, object in ipairs(objects) do
 -- object is on
 if toboolean(object.data) then
   delta = now - object.updatetime

   -- timer expired, turn off
   if delta >= ontime then
     object:write(0)
   end
 end
end

Using os.sleep and event script is not a good idea - each event script runs in a separate process which will be active for 4 hours. This will certainly exhaust all LM memory sooner or later. The system will reboot automatically in this case.

[RSV4]

Thank you very much! I thought that os.sleep() would not be a good idea from a resource point of view.

[Pawel]

There is some new(for me) commend (method?):  "object:write(0)". There is somewhere in manual comment about it? Maybe some other colon usage example?

[admin]

From Lua docs about colon (:) usage on strings:

The string library provides all its functions inside the table string. It also sets a metatable for strings where the __index field points to the string table. Therefore, you can use the string functions in object-oriented style. For instance, string.byte(s, i) can be written as s:byte(i).

Short example for objects:

Code:

obj = grp.find('1/1/1')

-- both lines do exactly the same thing
obj:write(false)
grp.write(obj.address, false, obj.datatype)

[edgars]

Another timer example.

Task: If there is 0 sent to grp address AND it stays for 30 min at this value, switch on relay for 3 min. This is used in sauna installation to drain water after sauning is finished.

Event script, input is binary object:

Code:

value = event.getvalue()

-- turn off timer and turn relay off
if value then
 storage.delete('timer')
 grp.write('1/1/1', false)
-- start timer if not already started
else
 timer = storage.get('timer')
 if not timer then
   storage.set('timer', 0)
 end
end

Scheduled script - run every minute:

Code:

-- check if timer is running
timer = storage.get('timer')
if timer then
 timer = timer + 1
 timer.set('timer', timer)

 -- turn relay on after 30 minutes
 if timer == 30 then
   grp.write('1/1/1', true)
 -- turn relay off after 33 minutes  
 elseif timer == 33 then
   grp.write('1/1/1', false)
 end
end

[managementboy]

Thanks! Here my version of the code. I use an object with a slider to allow us to set the auto-off value in minutes via the Visualization. I have it in a resident script with 60 seconds update. Works well.

Code:

ontime = grp.getvalue('9/4/0') * 60 -- autooff group in minutes * 60 seconds

-- current timestamp, in seconds
now = os.time()

-- get all objects with AutoOff tag
objects = grp.tag('AutoOff')

-- check all objects
for _, object in ipairs(objects) do
 -- object is on
 istrue = toboolean(object.data)
 if istrue then
   delta = now - object.updatetime
   -- timer expired, turn off
   if delta >= ontime then
     object:write(0)
   end
 end
end