Switch LCD on when passing by

Forums › Gadgets, robotics, home automation, electronics (including wearables) › Switch LCD on when passing by

ScuL

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#180674 17-Sep-2015 15:11

I'm thinking of a clever home information display showing some metrics such as weather info / bus times, with touch capability etc, running on a Raspberry Pi or so. To save on power consumption I don't want the screen on 24/7.
Instead, I would like to turn the screen on when somebody walks by it or stands in front of it (and then keep it on for another 120 seconds before going to standby again).

Are there any ready made sensor sockets/plugs available for AU/NZ plugs?
I have found them for US sockets.
http://www.amazon.com/SensorPlug-Motion-Activated-Electrical-Outlet/dp/B000A3CIUW/ref=sr_1_1?ie=UTF8&qid=1442459417&sr=8-1&keywords=sensor+plug

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lxsw20

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#1389107 17-Sep-2015 15:14

PDL do a sensor module for the 600 series, it's only rates to 750W so probably can't be used on a standard plug without some kind of relay (they do a relay module too). More designed for lighting applications.

SumnerBoy

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#1389109 17-Sep-2015 15:16

Good example of the power of openHAB - because it is completely device/protocol agnostic. You can have any sort of PIR sensor, whether it be Z-Wave, Arduino based, or even a pressure sensor on the floor, as long as you can get that event into the openHAB event bus, you can write a simple rule to detect that event and send a signal to the Raspberry Pi to turn on the display (and off again after 120 secs).

You can even run openHAB on the same Raspberry Pi!

If you are keen to tinker then a ESP8266 WIFI board with a cheap $2 PIR sensor attached would probably work just fine. You can program the ESP to publish events directly to openHAB via the REST API and you are 90% of the way there.

Aredwood

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#1389247 17-Sep-2015 19:08

If you have a security alarm that monitors that area. Use its PIR sensor to control your screen. And if you don't have an alarm. PIR sensors are easy to integrate.

ScuL

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#1389248 17-Sep-2015 19:14

Yeah I need to be sensible about the cat though, it will trip a normal PIR sensor. I was thinking of a sensor that could be mounted at a height the cat won't trip it

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timmmay

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#1389268 17-Sep-2015 19:46

The R.Pi needs to stay on, boot time makes the necessary. Instead of making it turn on when they walk past how about providing a simple button that tells the Pi to activate the screen. Set the screen timeout to 120 seconds using the OS. Simple, effective, easy.

Jase2985

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#1389277 17-Sep-2015 20:09

ScuL: Yeah I need to be sensible about the cat though, it will trip a normal PIR sensor. I was thinking of a sensor that could be mounted at a height the cat won't trip it

thats normally where you mount Alarm PIR's, and you can get pet friendly ones (ie wont pick up your pet). even most standard ones can be adjusted a little.

ScuL

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#1389288 17-Sep-2015 20:22

I get that, just feel getting an alarm or full home automation system is a bit overkill when a US switch is 20 bucks on Amazon :D

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Jase2985

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#1389303 17-Sep-2015 20:45

you dont need an alarm you just need the sensor to interface with a RPi to let it know when someone is around.

as timmay pointed out the bootup time would maybe defeat the purpose of it.

SumnerBoy

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#1389338 17-Sep-2015 21:41

openHAB is not a full home automation system...well it is...but it is just a bit of software you would run your Pi, as a conduit between the PIR (or whatever sensor you use) and your display software.