{HowTo} turn on/off your monitor (Time based, PIR/Button, App)

andi.aw.weiss

Hello everyone, I’m getting desperate. I’ve now read the entire tutorial but I can’t find my mistake.

I am using my MM with a PIR sensor and would like to switch the backlight of the display with a relay. so i use this script pir.py:

#!/usr/bin/env python

import sys
import time
import RPi.GPIO as io
import subprocess

io.setmode(io.BCM)
SHUTOFF_DELAY = 120 # in seconds, how long the monitor will be on until next button press or PIR detection
PIR_PIN = 22       # 15 on the board (this needn't to be a PIR. Can be a button also)
LED_PIN = 16      # optional

def main():
    io.setup(PIR_PIN, io.IN)
    io.setup(LED_PIN, io.OUT)
    turned_off = False
    last_motion_time = time.time()

    while True:
        if io.input(PIR_PIN):
            last_motion_time = time.time()
            io.output(LED_PIN, io.LOW)
            print ".",
            sys.stdout.flush()
            if turned_off:
                turned_off = False
                turn_on()
        else:
            if not turned_off and time.time() > (last_motion_time + 
                                                 SHUTOFF_DELAY):
                turned_off = True
                turn_off()
            if not turned_off and time.time() > (last_motion_time + 1):
                io.output(LED_PIN, io.HIGH)
        time.sleep(.1)

def turn_on():
	subprocess.call("sh /home/pi/monitor_on.sh", shell=True)

def turn_off():
	subprocess.call("sh /home/pi/monitor_off.sh", shell=True)

if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        io.cleanup()

Unfortunately, when I run this script in the terminal, I only get the feedback from the PIR sensor (…) but the relay is not switched. But if I run the monitor_on.sh or monitor_off.sh script it works:

monitor_on.sh

gpio -g mode 27 out
sleep 0.2
gpio -g write 27 1

monitor_off.sh

gpio -g mode 27 out
sleep 0.2
gpio -g write 27 0

But the PIR.py doesn’t work. Where could the mistake lie?

Many greetings Andreas

MadScientist

@andi-aw-weiss I think you are using the wrong script. With just a quick look it seems you’re running the script from point 2.2 (Using PIR script) of the first post. What you want is point 5.2 (Use relay with a PIR). That script used in 5.2 is different than that of 2.2, which does not have code to control the relay.

Have a look at it again.

andi.aw.weiss

@MadScientist Hey, unfortunately the problem hasn’t changed. I have now like you said the script from 5.2. The problem remains. PIR detects motion. Relay does not switch. :loudly_crying_face: I don’t know

andi.aw.weiss

@MadScientist ok it seems to be working now. However, the relay switches the first time after the 120 s have expired and a movement is detected. not previously. The change quote: “io.output(RELAY_PIN, False)” and for monitor off “io.output(RELAY_PIN, True)” only causes the relay to work in reverse. I now use this script:

#!/usr/bin/env python

import sys
import time
import RPi.GPIO as io
import subprocess

io.setmode(io.BCM)
SHUTOFF_DELAY = 120 # in seconds, how long the monitor will be on until next button press or PIR detection
PIR_PIN = 22       # 15 on the board (this needn't to be a PIR. Can be a button also)
LED_PIN = 17    # 11 on the board (optional): It just shows detection time of PIR without delay time
RELAY_PIN = 27  # 13 on the board

def main():
    io.setup(PIR_PIN, io.IN)
    io.setup(LED_PIN, io.OUT)
    io.setup(RELAY_PIN, io.OUT)
    turned_off = False
    last_motion_time = time.time()

    while True:
        if io.input(PIR_PIN):
            last_motion_time = time.time()
            io.output(LED_PIN, io.LOW)
            print ("."),
            sys.stdout.flush()
            if turned_off:
                turned_off = False
                turn_on()
        else:
            if not turned_off and time.time() > (last_motion_time + 
                                                 SHUTOFF_DELAY):
                turned_off = True
                turn_off()
            if not turned_off and time.time() > (last_motion_time + 1):
                io.output(LED_PIN, io.HIGH)
        time.sleep(.1)

def turn_on():
        io.output(RELAY_PIN, True)

def turn_off():
        io.output(RELAY_PIN, False)

if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        io.cleanup()

where could the error lie? or is that how it should be? Thank you MadScientist

cruunnerr

@andi-aw-weiss

Hey hey,

So what exactly doesn’t work? My English isn’t the best

In my case I am turning on a LED Stripe with the pir.

When I cold start the raspi, the LED stripe turns on for a few seconds (could be the turnoff delay time).
After a while it turns off.
From this moment on it should work as you expect. When movement is detected, the led (or relay) turns on for the delay time and extend the delay time for every new movement within the original delay time.

MadScientist

@andi-aw-weiss said in {HowTo} turn on/off your monitor (Time based, PIR/Button, App):

The change quote: “io.output(RELAY_PIN, False)” and for monitor off “io.output(RELAY_PIN, True)” only causes the relay to work in reverse. I now use this script:

Are you saying the screen turns off when the PIR detects a motion? In that case you have to change the the terminals on the relay. You have three terminals to connect the wires to. GND, normal open and normal close.

Another note: I have a bunch of relays here that are supposed to be compatibles with Raspberry Pi’s but somehow they don’t properly work. They switch exactly once and then are stuck. Not sure if you’re having the same issues.

andi.aw.weiss

@cruunnerr @MadScientist Thanks to both of you . For development/tutorial and support. My MM works. I was probably impatient the whole time I was testing. The relay only switches for the first time after the 120 s have expired. But that’s ok that it only occurs when you restart. I consider the problem solved. THANK YOU

nowayto

Hello, I know this is an old topic but I think it’s very interesting.

I have an idea but I’m a newbie to programming.
In my mind I was thinking about using one or more modules like these:

MMM-ModuleScheduler
MMM-Home-Presence
MMM-RemoteControl

to have a way to turning off the monitor when one member of the family is at home.

For “is at home” I mean when the phone is connected to wifi and the MMM-Home-Presence detect his presence.

Might be MMM-RemoteControl could communicate with MMM-Home-Presence and turn off/on the monitor?

What do you think about it?
Thanks

sdetweil

@nowayto you CAN compose a solution like that.

However Home-Presence does not inform other modules about state of devices

It could’ve extended to do that

Then you could config Remote-Controlto respond to that

nowayto

@sdetweil ok, I don’t think a newbie like me could do it but it was a good idea, if only Home-Presence had a notification option by default. Thanks

sdetweil

@nowayto try my updated fork

https://github.com/sdetweil/MMM-home-presence

a new config parm

  notification:"some_string",  // some_string  can be anything you want. 
  default "", //no notification will be sent.. just like normal

this is the notification key that will be sent
the payload will be
true, if at least one of the phones on the list is present
false, if none of the phones in the list are present

nowayto

@sdetweil Oh, thank you!
So you modify the module to send notification when it detect one or more presence?
I installed it and configure the notification “string”
Now I have a module that send a virtual notification “string” to other modules.
So now I’m toughing about install MMM-RemoteControl and MMM-ModuleScheduler.

When someone is at home ModuleScheduler will receive the “string” and it will send a command to RemoteControl for turning on the display.
And when no one is at home? ModuleSchedule won’t receive any notification so RemoteControl should exec the MONITOROFF commands.
I know it can’t work like this, maybe I’ve lost some steps in my mind.

I was also thinking about the electronics I’m using.
Mine is an LCD taken from a digital frame, connected to rasbperry through a lcd controller.
The controller turning off monitor itself when there isn’t hdmi signal for a while and it should stay in stand-by waiting for signal.
My doubts are:

In your opinion, module will send command every 10 seconds, so is this could be a problem?
Do you have experience if the “MONITORON” “MONITOROFF” commands acts as CEC commands or a simple “turning ON/OFF the raspberry’s video out”?
Because if it work as CEC command… I think it will not work, in my case with an LCD controller

nowayto

@sdetweil noticed another little problem. My phone is connected to wifi but the flag on Home-Presence turn off sometimes, especially when the screen is locked.
I tried to disable the “wifi private address option” on the phone and it seem working well but sometimes the flag goes off so I suppose that, after configuration, the monitor will turn on off itself a lot of times

sdetweil

@nowayto the home presence module updates the display every interval_ms , the device status could change that often.

currently the notification is sent every time the display updates, regardless of device status

so you would get 30 messages sent per minute (using the sample config, the default is only 100 ms, so 200 times more per minute, 10 times per second)

I think it should only send on change, and can fix that

I do not know how reliable the presence test is, hackers and privacy protection make simple ideas very hard

sdetweil

@nowayto I changed the module to only send notification when there is a change
so it is not sending same state over and over …

git pull in the module folder and restart MagicMirror

sdetweil

@nowayto

Do you have experience if the “MONITORON” “MONITOROFF” commands acts as CEC commands or a simple “turning ON/OFF the raspberry’s video out”?
Because if it work as CEC command… I think it will not work, in my case with an LCD controller

CEC requires some computer processor in the display to handle the commands being sent,
AND it requires a 2 way HDMI port (HDMI 1.3 or above I think)

after 2016, all monitors/tvs/displaye to be energystar compliant are required to power off (not standby) after detecting no input signal… SO, if you turn off the HDMI port (what we all did prior to energystar) you get a big screen
NO INPUT until the timeout (15 mins by default)

pi3 do NO have the bidi HDMI port, so CEC won’t work there…
and we have ALL been trying to find alternative methods since then
AND the OS versions have been changing the commands used as well…

nowayto

@sdetweil So in your opinion my idea Home-Presence+RemoteControl+Scheduler could work?
Or should I have to throw it in the wastebin? :)

sdetweil

@nowayto i do not know if THAT combination works…

but given a notification, SOME collection should work.
maybe your notification should be USER_PRESENCE (true/false)

other modules respond to that

nowayto

@sdetweil
Yes, I knew how CEC work, but in my case I have an LCD controller and I have check his behaviour.

Lucky me, when video signal is off, the controller stay in standby with a completely black screen.
This will be perfect, but only if the RemoteControl command will stop or cut-off the video signal, instead of sending a CEC turning off signal.
That was my doubt

sdetweil

@nowayto use the wrandr/xrandr command to turn off the hdmi port
w = wayland
x = x11

depending on the display manager