EcoLow
Posts: 11
Joined: Sat Oct 08, 2016 11:22 pm

DIY IR beam break

Sun Oct 09, 2016 12:30 am

Hi everyone !

I always forget to turn my lights off. Just as i type this in my living room, the kitchen lights are on... Not really Eco friendly nor wallet friendly, plus, it's getting my girlfriend crazy... I have to do something.
The solution ? Well, i am a capable geek with a Pi, so ... home automation !
I have done a fair bit of research the last few weeks and i want to go for something like this .
Yes, i could use some simple movement detectors but they have a tendency to lag (nothing worse for me) and they have a "dangerous" factor in the bathroom. They can't really detect "presence".

I have seen that Adafruit is selling these IR Break Beam Sensor, but their range is too short (50cm tops, when a door is around 90cm). Plus it wouldn't really be cost effective, 13$ for each doors is a bit out of my budget). Meaning i need to go completely DIY ! Something like this?

I think that in short, i need an IR LED, some resistors and an IR phototransistor.
Any suggestions ?

I would like to control all three doors with only one Pi but i am not sure if the Pi is going to have enough power for this.

How far can the Pi be, at maximum , from the LED or receiver ? (i hear something about the current getting lower with the distance).

Sorry for this long long question and thanks for the answers in advance !
Cheers.

EcoLow
Posts: 11
Joined: Sat Oct 08, 2016 11:22 pm

Re: DIY IR beam break

Sun Oct 09, 2016 9:24 pm

For future googlers wondering about the voltage drop : http://www.calculator.net/voltage-drop-calculator.html
In my situation, totally doable (we have a 30m²).

A GPIO can only draw a maximum of 16mA, 50mA in total accross the board. I will have to get an external power supply and control the LEDs via transistors.

Remaining questions :
- What IR LEDs and sensors should i use to get a 90cm range ?
- How should i go about supplying power to 8 LEDs and sensor combos ?

boyoh
Posts: 1528
Joined: Fri Nov 23, 2012 3:30 pm
Location: Selby. North Yorkshire .UK

Re: DIY IR beam break

Sun Oct 09, 2016 10:10 pm

EcoLow wrote:Hi everyone !

I always forget to turn my lights off. Just as i type this in my living room, the kitchen lights are on... Not really Eco friendly nor wallet friendly, plus, it's getting my girlfriend crazy... I have to do something.
The solution ? Well, i am a capable geek with a Pi, so ... home automation !
I have done a fair bit of research the last few weeks and i want to go for something like this .
Yes, i could use some simple movement detectors but they have a tendency to lag (nothing worse for me) and they have a "dangerous" factor in the bathroom. They can't really detect "presence".

I have seen that Adafruit is selling these IR Break Beam Sensor, but their range is too short (50cm tops, when a door is around 90cm). Plus it wouldn't really be cost effective, 13$ for each doors is a bit out of my budget). Meaning i need to go completely DIY ! Something like this?

I think that in short, i need an IR LED, some resistors and an IR phototransistor.
Any suggestions ?

I would like to control all three doors with only one Pi but i am not sure if the Pi is going to have enough power for this.

How far can the Pi be, at maximum , from the LED or receiver ? (i hear something about the current getting lower with the distance).

Sorry for this long long question and thanks for the answers in advance !
Cheers.
What is a Geek with the Raspberry Pi, asking questions, he seems to know the answers to
BoyOh ( Selby, North Yorkshire.UK)
Some Times Right Some Times Wrong

BMS Doug
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Re: DIY IR beam break

Sun Oct 09, 2016 10:38 pm

boyoh wrote: What is a Geek with the Raspberry Pi, asking questions, he seems to know the answers to
Perhaps the act of formulating his post gave him an insight into the solution?
Doug.
Building Management Systems Engineer.

stderr
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Joined: Sat Dec 01, 2012 11:29 pm

Re: DIY IR beam break

Sun Oct 09, 2016 10:46 pm

boyoh wrote: What is a Geek with the Raspberry Pi, asking questions, he seems to know the answers to
That's a good question but the real question is why you didn't warn him about the danger of mains voltages.

EcoLow
Posts: 11
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Re: DIY IR beam break

Sun Oct 09, 2016 10:52 pm

BMS Doug wrote:
boyoh wrote: What is a Geek with the Raspberry Pi, asking questions, he seems to know the answers to
Perhaps the act of formulating his post gave him an insight into the solution?
That and if my reasoning goes south, i hoped to be corrected. Plus get some useful hints !

Thanks for the Main's heads up, but i goes without saying.
No guts no glory ...

stderr
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Joined: Sat Dec 01, 2012 11:29 pm

Re: DIY IR beam break

Sun Oct 09, 2016 11:05 pm

EcoLow wrote:I always forget to turn my lights off.
I think there's a huge amount of room in this but it's not as easy as you make it if you get beyond just being a dummy and leaving lights on for hours that aren't in use for no reason other than you can't bother to flip the switch, not that that's a rare issue for any of us. Fixing that isn't that hard, it's fruit just a little higher up the tree than changing your incandescents out for fluorescents.

But what would really be a sea change is to be able to sense when you are actually using a specific light and if you aren't, even for a few moments, shut it off. For example, you are cooking dinner and you are moving from the stove to the sink. The light above the stove could go off when you turn away and walk to the sink which would then have its light go on which would go off if you went to a counter to cut asparagus. Today, all these lights would usually be on all the time you are in the kitchen.

There could be a lower level area light that was on while you were in the kitchen if you found the sudden light changes disconcerting. This idea could be generalised, as you walk around the house, depending on factors like outside light and the time of day, the lights that you set this way could go on and off. Even the backlight on the computer monitors and TV could go off it was designed with LED backlighting.

But designed in use constraints are really an issue with this and even with what you are talking about. Are you using LED lighting? Even mains LED lighting uses a power supply or converter that changes mains to the lower voltage that the LEDs need. How many times can these things be turned on and off before they break? I bet it's way lower than the LEDs themselves which people routinely use with PWM. So ultimately what is needed, I suspect, is 12 volt DC lighting in the home, purpose built to not have problems with this usage pattern. I suspect that would be true of your TV too, I bet that its backlight, even if it is LED, potentially could have troubles if you cycled it at every commercial and every time you go up for more popcorn.

EcoLow
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Re: DIY IR beam break

Sun Oct 09, 2016 11:32 pm

stderr wrote: But what would really be a sea change is to be able to sense when you are actually using a specific light and if you aren't, even for a few moments, shut it off. For example, you are cooking dinner and you are moving from the stove to the sink. The light above the stove could go off when you turn away and walk to the sink which would then have its light go on which would go off if you went to a counter to cut asparagus. Today, all these lights would usually be on all the time you are in the kitchen.
I actually thought about that for the bathroom. With a distance sensor, i could probably turn my mirror's light on/off when i actually need them ...
Total overkill, but I guess that with enough sensors and a ton off logic and trial and error, your kitchen idea could be done too. Maybe a pressure sensors under the floors ?
stderr wrote: There could be a lower level area light that was on while you were in the kitchen if you found the sudden light changes disconcerting. This idea could be generalised, as you walk around the house, depending on factors like outside light and the time of day, the lights that you set this way could go on and off. Even the backlight on the computer monitors and TV could go off it was designed with LED backlighting.
That or dimming lights. But even than, i think that you would be fairly disturbed. Imagine you have to watch your eggs while washing your hands...

Good point for time of the day, a ambient light sensor ? Gets pretty dark in winter ...

I already thought about the computer's LCD turning off but it would be fairly impossible to determine when it really needs to be turned off. I some situations, you want to watch something from more than the usual distance (ex. when cooking). And you cannot turn your TV on and off everytime you get popcorn.
stderr wrote: But designed in use constraints are really an issue with this and even with what you are talking about. Are you using LED lighting? Even mains LED lighting uses a power supply or converter that changes mains to the lower voltage that the LEDs need. How many times can these things be turned on and off before they break? I bet it's way lower than the LEDs themselves which people routinely use with PWM. So ultimately what is needed, I suspect, is 12 volt DC lighting in the home, purpose built to not have problems with this usage pattern. I suspect that would be true of your TV too, I bet that its backlight, even if it is LED, potentially could have troubles if you cycled it at every commercial and every time you go up for more popcorn.
Just basic incandescent lights, but does it matter ?
I mean, wouldn't it be just the same than "getting beyond just being a dummy" and turn my lights off every time i leave the room ?

boyoh
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Location: Selby. North Yorkshire .UK

Re: DIY IR beam break

Mon Oct 10, 2016 8:26 am

EcoLow wrote:
stderr wrote: But what would really be a sea change is to be able to sense when you are actually using a specific light and if you aren't, even for a few moments, shut it off. For example, you are cooking dinner and you are moving from the stove to the sink. The light above the stove could go off when you turn away and walk to the sink which would then have its light go on which would go off if you went to a counter to cut asparagus. Today, all these lights would usually be on all the time you are in the kitchen.
I actually thought about that for the bathroom. With a distance sensor, i could probably turn my mirror's light on/off when i actually need them ...
Total overkill, but I guess that with enough sensors and a ton off logic and trial and error, your kitchen idea could be done too. Maybe a pressure sensors under the floors ?
stderr wrote: There could be a lower level area light that was on while you were in the kitchen if you found the sudden light changes disconcerting. This idea could be generalised, as you walk around the house, depending on factors like outside light and the time of day, the lights that you set this way could go on and off. Even the backlight on the computer monitors and TV could go off it was designed with LED backlighting.
That or dimming lights. But even than, i think that you would be fairly disturbed. Imagine you have to watch your eggs while washing your hands...

Good point for time of the day, a ambient light sensor ? Gets pretty dark in winter ...

I already thought about the computer's LCD turning off but it would be fairly impossible to determine when it really needs to be turned off. I some situations, you want to watch something from more than the usual distance (ex. when cooking). And you cannot turn your TV on and off everytime you get popcorn.
stderr wrote: But designed in use constraints are really an issue with this and even with what you are talking about. Are you using LED lighting? Even mains LED lighting uses a power supply or converter that changes mains to the lower voltage that the LEDs need. How many times can these things be turned on and off before they break? I bet it's way lower than the LEDs themselves which people routinely use with PWM. So ultimately what is needed, I suspect, is 12 volt DC lighting in the home, purpose built to not have problems with this usage pattern. I suspect that would be true of your TV too, I bet that its backlight, even if it is LED, potentially could have troubles if you cycled it at every commercial and every time you go up for more popcorn.
Just basic incandescent lights, but does it matter ?
I mean, wouldn't it be just the same than "getting beyond just being a dummy" and turn my lights off every time i leave the room ?
ECO........I liken you to a Parrot, You can teach a Parrot to recite OHM's LAW
But it as no Idea what it is talking about
BoyOh ( Selby, North Yorkshire.UK)
Some Times Right Some Times Wrong

EcoLow
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Joined: Sat Oct 08, 2016 11:22 pm

Re: DIY IR beam break

Mon Oct 10, 2016 11:24 am

boyoh wrote:
ECO........I liken you to a Parrot, You can teach a Parrot to recite OHM's LAW
But it as no Idea what it is talking about
Let's not get carried out with unnecessary insults to anyone's intellect based on ill-founded impressions and concentrate at the problem at hand, please...

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Ronaldlees
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Re: DIY IR beam break

Mon Oct 10, 2016 1:00 pm

EcoLow wrote:
boyoh wrote:
ECO........I liken you to a Parrot, You can teach a Parrot to recite OHM's LAW
But it as no Idea what it is talking about
Let's not get carried out with unnecessary insults to anyone's intellect based on ill-founded impressions and concentrate at the problem at hand, please...
+1

Why post that stuff? Adds nothing.

I would consider switching over to LED devices for this project, because turning incandescent bulbs off and on frequently drastically shortens their lifetime. Once you've switched to LEDs, then the bigger eater of amperes is going to be the decision time spent standing in front of the refrigerator!

So, maybe another Pi project to consider is putting a camera in the frig, and doing the decision-making via your Pi's web pages.
I am the Umbrella man

EcoLow
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Re: DIY IR beam break

Mon Oct 10, 2016 2:24 pm

Ronaldlees wrote: I would consider switching over to LED devices for this project, because turning incandescent bulbs off and on frequently drastically shortens their lifetime. Once you've switched to LEDs, then the bigger eater of amperes is going to be the decision time spent standing in front of the refrigerator!
Thanks for the input, i will replace them as they fail... Or go for some Philips Hue, so that i don't have to mess too much with the Mains.

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bensimmo
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Re: DIY IR beam break

Mon Oct 10, 2016 3:00 pm

The power saved with LED lighting and leaving them on, out ways the process of getting something to turn a normal or CFL (energy saver) bulb.

1000lumens is about 13W now for about £8, which I think are the 100W+ equivalents.
So a bright bulb and still 230V
A Pi being 2W to 5W draw from its PSU and that will always be on.

That's the first job, then look to saving power by getting them turned of.
Remember though that the Pi, it's sensor, it's LED and it's PSU for 5V (or laser as they tend to be more useful for this) will all be using electricity.


BUT
For a project..
I would use a laser at one side, you can then shine this on an LDR and use a simple potential divider circuit you can have it ignore the background light easily

Use gpiozero and it's really simple, then just control your switch for the mains light.
Get dimmable lights and you can have them adjust brightness during the day if you can work out the switching for it.

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bensimmo
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Re: DIY IR beam break

Mon Oct 10, 2016 3:07 pm

Saying that a more power efficient sensor and it only need on set of wires (since all I can see is you are sensing a door open) is to use a read switch setup. When it off there is no power through that part of the circuit, when door opens you have it make the circuit and job done.

But a door doesn't detect presence.
It would be better than have a laser bounce of mirrors around your room area so you can cover someone being anywhere in the room ;-)

stderr
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Re: DIY IR beam break

Mon Oct 10, 2016 6:00 pm

bensimmo wrote:it's sensor, it's LED and it's PSU
There are impressionable children possibly reading this website, think about the long term damage that might result in them seeing this three in a row. The possessive of it is its, it is not it's which is the contraction of it is. Thank you for your consideration and help fighting this highly contagious global internet pandemic.
1000lumens is about 13W now for about £8, which I think are the 100W+ equivalents.
One thing that seems to be the case is that the light makers are currently claiming LED light energy usages and not including the power used in anything but the actual LED diodes themselves. This doesn't include the power supply conversion from mains to the voltages used by the LEDs which is a big deal if the actual power used is perhaps 20% more.
Get dimmable lights and you can have them adjust brightness during the day if you can work out the switching for it.
How efficient is the dimming and most LED lights claim to be non-dimmable, although I'm not sure exactly what this means, perhaps non-dimmable using the usual incandescent dimming schemes, I don't know. The problem goes back to the power supplies for the LEDs, which is another reason why home lighting should be migrating towards 12 volt DC.

EcoLow
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Re: DIY IR beam break

Mon Oct 10, 2016 6:31 pm

I didn't realise how power efficient they were. It's crazy how much you can overlook a problem sometimes ...

It's incredible that i haven't heard about that earlier.
But at the same time, i live in Germany and they are, to put it nicely, LATE technology wise.

Anyway, i just checked with the miss and she doesn't care. The lights needs to be off no matter what...

The Pi won't be used, only, to switch lights on and off. This is just a first step into my home's automation.

Thank you so much for the insights about the lasers and all, i'll check that out ASAP.

The door switch is a good idea but i don't want my lights to turn off every times my girlfriend goes to another room.

Another possible solution poped in my mind : what if, rather than using two Beam break, i go for two proximity sensors ?

ewaller
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Re: DIY IR beam break

Mon Oct 10, 2016 6:54 pm

I am coming to this a bit late, sorry.

It turns out you can drive an IR LED very hard for a short period of time. I don't know how those Adafruit sensors are configured, but, in general, you can drive an LED at high current for a several 10s of microseconds followed by leaving them off for 10s of milliseconds. The limitations are the maximum average power and the absolute peak current specifications for the part. As long as you only poll the detector while the transmitter is enabled, you can get much more range out of the system. The nice thing about this system is that you can time multiplex the sensors and only turn on one at a time.

For example, the following part is limited to a continuous forward current of 100mA. It will, however, take 1A of forward current for 100uS followed by a 10mS rest. So, (quickly) turn it on, look at the detector output, and shut it off. I'd expect you get about an order of magnitude more range.

http://www.everlight.com/file/ProductFi ... 067600.pdf

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bensimmo
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Re: DIY IR beam break

Mon Oct 10, 2016 7:08 pm

EcoLow wrote:I didn't realise how power efficient they were. It's crazy how much you can overlook a problem sometimes ...

It's incredible that i haven't heard about that earlier.
But at the same time, i live in Germany and they are, to put it nicely, LATE technology wise.

Anyway, i just checked with the miss and she doesn't care. The lights needs to be off no matter what...

The Pi won't be used, only, to switch lights on and off. This is just a first step into my home's automation.

Thank you so much for the insights about the lasers and all, i'll check that out ASAP.

The door switch is a good idea but i don't want my lights to turn off every times my girlfriend goes to another room.

Another possible solution poped in my mind : what if, rather than using two Beam break, i go for two proximity sensors ?
I must have misunderstood somewhere, how do you intend the 'IR beam' to work, they act as a switch? Much like a door switch. How do you intend them to know you are in the room?

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bensimmo
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Re: DIY IR beam break

Mon Oct 10, 2016 7:28 pm

stderr wrote:
bensimmo wrote:it's sensor, it's LED and it's PSU
There are impressionable children possibly reading this website, think about the long term damage that might result in them seeing this three in a row. The possessive of it is its, it is not it's which is the contraction of it is. Thank you for your consideration and help fighting this highly contagious global internet pandemic.
1000lumens is about 13W now for about £8, which I think are the 100W+ equivalents.
One thing that seems to be the case is that the light makers are currently claiming LED light energy usages and not including the power used in anything but the actual LED diodes themselves. This doesn't include the power supply conversion from mains to the voltages used by the LEDs which is a big deal if the actual power used is perhaps 20% more.
Get dimmable lights and you can have them adjust brightness during the day if you can work out the switching for it.
How efficient is the dimming and most LED lights claim to be non-dimmable, although I'm not sure exactly what this means, perhaps non-dimmable using the usual incandescent dimming schemes, I don't know. The problem goes back to the power supplies for the LEDs, which is another reason why home lighting should be migrating towards 12 volt DC.
It can annoy me too, but the world needs better in context autocorrects. I certainly didn't put the apostrophes there. Normally I would correct them, but the forum a touchscreen display don't make it the easiest thing to alter, so I give up now :shock: Even with the nice slide on the space to move back and forth.

I think with LEDs it actual power usage as a device, how could they claim anything else, it's not output power. I can check and stick it on a power meter.
At least in the EU as they have the EnergyRating so they cannot hide it and the Ikea ones tell you it in kWh too.

They flash the LED at different frequencies to dim the LEDs, current drop and led dropout if it's multi led, most are capable now. Some use better methods and you pay more for them not to have horrible closer or hum.
Bulb, GUs etc
I've been using LEDs in house lights for a long time now, they used to be poor, bit now I would choose nothing else.

I'm all for 12V, but they would need a large transformer near the consumer box and an efficient way to distribute it around the house. Not this transformer near every few lights.


(I pick IKEA as an example as they have a lot of different and nice designs)

EcoLow
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Re: DIY IR beam break

Tue Oct 11, 2016 11:43 am

bensimmo wrote: I must have misunderstood somewhere, how do you intend the 'IR beam' to work, they act as a switch? Much like a door switch. How do you intend them to know you are in the room?
It's i my original post, first link, you should really have a look :
EcoLow wrote: I have done a fair bit of research the last few weeks and i want to go for something like this .


By using two IR Beam Break in parallel on each door, you can count people and you sense the direction of their movement.
The logic gets pretty easy from that point on... He says the accuracy is between 95 and 99% with some coding "tricks".

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bensimmo
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Re: DIY IR beam break

Tue Oct 11, 2016 4:08 pm

Completely missed the tiny link you made, it's probably best to leave them as big obvious links.
I did see and have a quick look at the adafruit one though.

Nice read through, give it a go.

boyoh
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Re: DIY IR beam break

Tue Oct 11, 2016 6:49 pm

EcoLow wrote:
boyoh wrote:
ECO........I liken you to a Parrot, You can teach a Parrot to recite OHM's LAW
But it as no Idea what it is talking about
Let's not get carried out with unnecessary insults to anyone's intellect based on ill-founded impressions and concentrate at the problem at hand, please...
ECO
Please except my apologies for the Inappropriate remark
Yes it was well lout of line

Regards BoyOh
BoyOh ( Selby, North Yorkshire.UK)
Some Times Right Some Times Wrong

stderr
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Re: DIY IR beam break

Tue Oct 11, 2016 7:44 pm

bensimmo wrote:I think with LEDs it actual power usage as a device, how could they claim anything else, it's not output power.
How could they claim anything else? These are people in marketing, not engineering, it's their job.
I can check and stick it on a power meter.
I can't find where I've read that the claimed power usage doesn't include the driver/ballast, so it would be interesting. I wonder if the claimed power usage of bulbs sold in the EU is the same as the claimed power usage of bulbs that are exactly the same that are sold in the US. But a direct check and comparison with the claimed usage in your context would be useful, I think.
They flash the LED at different frequencies to dim the LEDs, current drop and led dropout if it's multi led, most are capable now. Some use better methods and you pay more for them not to have horrible closer or hum.
Except that if you have a bulb that is running on mains voltage, it has to have a driver of some sort. Those seem to be the major problem with longevity and with not being able to dim properly or acceptably at least in the view of the manufacturer.
I'm all for 12V, but they would need a large transformer near the consumer box and an efficient way to distribute it around the house. Not this transformer near every few lights.
Generating the 12 volts without losses to whatever best degree you can do that is clearly something that needs a good answer to make this work. But doing this conversion in every light bulb is also clearly not a good answer even just because the heat that incandescent bulbs can stand tend to kill LEDs and fluorescents. We also need a way to run the LEDs directly from the 12 volts while considering all failure modes.

boyoh
Posts: 1528
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Re: DIY IR beam break

Wed Oct 12, 2016 8:22 pm

EcoLow wrote:Hi everyone !

I always forget to turn my lights off. Just as i type this in my living room, the kitchen lights are on... Not really Eco friendly nor wallet friendly, plus, it's getting my girlfriend crazy... I have to do something.
The solution ? Well, i am a capable geek with a Pi, so ... home automation !
I have done a fair bit of research the last few weeks and i want to go for something like this .
Yes, i could use some simple movement detectors but they have a tendency to lag (nothing worse for me) and they have a "dangerous" factor in the bathroom. They can't really detect "presence".

I have seen that Adafruit is selling these IR Break Beam Sensor, but their range is too short (50cm tops, when a door is around 90cm). Plus it wouldn't really be cost effective, 13$ for each doors is a bit out of my budget). Meaning i need to go completely DIY ! Something like this?

I think that in short, i need an IR LED, some resistors and an IR phototransistor.
Any suggestions ?

I would like to control all three doors with only one Pi but i am not sure if the Pi is going to have enough power for this.

How far can the Pi be, at maximum , from the LED or receiver ? (i hear something about the current getting lower with the distance).

Sorry for this long long question and thanks for the answers in advance !
Cheers.
One way is to have a high current 12vdc power supply in a convenient position
Split the out put through several MCB's for protection, LED lighting could be don
Connecting the LED's in clusters, connecting them in Series Parallel circuits
6 led connected in series on 12v, calculate limiting resistor to allow 20ma
You could parallel more series led's to this, You might be able to buy LED
Clusters that you could modify

There are PIR 360 Presence Detectors you can buy for room control
BoyOh ( Selby, North Yorkshire.UK)
Some Times Right Some Times Wrong

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