Hide modules when display goes off through PIR (power saving)

ejay-ibm

@thedk Hi ,
I finally manage to find a solution that works quite good.
I do not deserve the credit for the solutions, only for the implementation as it merges multiple sources.
First : PIR need a first trigger to work .
Workaround : Make the HDMI OFF when the mirror start ( so your screen doesn’t stay ON always until someone pass in front of the miror )

For this Edit :
in the MMM-PIR-SENSOR folder
node_helper.js
around line 139

this.started = true;
    self.deactivateMonitor();  // add this to turn off monitor at startup .

Then to deactivate the idle / sleep mode of the modules due to MMM-Assistant

Still in the node_helper.js modify line 34 like :

exec(“/usr/bin/vcgencmd display_power 1 && xdotool key ctrl+r”, null); // add here xdotool key ctrl+r

You need to install xdotool for this. That will allow to simulate the ctrl+r from keybaord that refresh the module therefore bring them back on screen .

I set in the config.js file the pir module to put the screen off after 15 mins

“powerSavingDelay”: “900”,

I applied the same setting in MMM-AssistantMk2.js

onIdle: {
timer: 10006015, // if you don’t want to use this feature, just set timer as 0 or command as “”
command: “HIDEMODULES”

Summary When I start my mirror the screen is off. The PIR detect my presence and turn it ON .
After 15 mins the screen goes off and the modules goes in sleep .

As soon as the user presence is detected again , the screen goes on and modules are refreshed and come back .

Hope this helps .

EJ

broberg

Maybe I don’t understand your question… but

Hiding modules only with css (i.e hiding them on screen) does nothing for the power saving.
You need the monitor to go in to sleep for any power to be saved.

The Pi still runs when you hide the modules, not much power to save there, And I don’t really think the modules reload when hiding/showing them. But I can be wrong haven’t looked in to the code on the Hide/show part.

sdetweil

modules do not reload… their content is not shown when hidden

thedk

But it would save CPU Power if the Modules would be hide or not?

sdetweil

@thedk unlikely… or so small as to be unmeasurable

ejay-ibm

@broberg
Indeed you don’t save power but when placing the module “on sleep” you stop them for making them network request with API calls .

sdetweil

@ejay-ibm yes, a well written module will suspend operations while hidden or suspended.

cowboysdude

@sdetweil I’d be willing to bet the majority don’t … I don’t have any provisions in mine to stop polling but since you brought it up it is something I will most certainly want to do!! It’s a VERY good idea!

Mykle1

@sdetweil said in Hide modules when display goes off through PIR (power saving):

a well written module will suspend operations while hidden or suspended.

That leaves me out. :-)

sdetweil

@cowboysdude @Mykle1 just add routines for suspend and resume. Set a variable on suspend, and don’t do anything til the variable is cleared on resume

j.e.f.f

@sdetweil said in Hide modules when display goes off through PIR (power saving):

@thedk unlikely… or so small as to be unmeasurable

Also, if the modules keep running while the display is off, they will all be up to date when you trigger the presence sensor to bring it out of sleep.

I’d recommend not hiding the modules during power save.

sdetweil

@j-e-f-f I have a mopdule that tracks water usage and tank levels, once every 5 minutes… calls an api, gets all the values, and draws the graphs…

my SleepWake module puts the mirror to sleep when no one is around… but when it wakes up, it updates…
in like 5-10 seconds…

no point pulling all that data overnight, or when I am gone for the day…

thedk

Nice discussion :)
My thought just was to reduce the temperature of the CPU when the display switches of.
But the point with the network requests is also good!

cowboysdude

@thedk Well if it’s not pulling it may cool it down by the virtue of not having to work to get the data. The other way to cool it down is put a fan on or near it…

j.e.f.f

@cowboysdude a fan adds noise. If you’re really concerned about heat, then suspending the modules when it goes to sleep is a good approach if you’re ok with waiting 5-10 seconds for your modules to update after your mirror wakes up.

thedk

A fan wouldnt be a solution. The 5-10 seconds waiting would be ok.

sdetweil

@j-e-f-f if I am willing to wait 5 minutes for the next update, why would I NOT be willing to wait 5-10 SECONDS for a refresh after sleeping all night?

I don’t sleep the mirror for power or heat savings…(cpu runs at the same speed al the time) I sleep the mirror for darkness…