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[on:]

Hi!

I would like to build a simple IR barrier
sensor and wondered how to wire it.

Any simple ciruits out there?

Thanks!

[Reply #1 on:]

Thank you for your reply!

I would like to avoid environmental interferences so
how to modulate a IR signal?

What I want to do is:
1. Understand how to build a sensor like this
in general for future projects.

2. Maybe I want to build a machine to sort
coins so I would like to detect the size of
a coin and if a coin has reached a physical
place in the machine.

I have this IR phototransistor (BP 103B-2)
http://www.reichelt.de/index.html?;ACTION=7;LA=3;OPEN=0;INDEX=0;FILENAME=A500%252FBP103B-2%25231-SIA.pdf;SID=10TYSDAn8AAAIAAFkvFsI32c230ac46baf28788bb49e3707c7d18

And this IR LED (LD 274-3):
http://www.reichelt.de/index.html?;ACTION=7;LA=3;OPEN=0;INDEX=0;FILENAME=X100%252Fld_274-3.pdf;SID=10TYSDAn8AAAIAAFkvFsI32c230ac46baf28788bb49e3707c7d18

I also have a BPW 42 phototransistor As well As a SFH 409 IR LED.

Thank you very much!!

[Reply #2 on:]

Links work for me, opens into pdf docs.

Lefty

[Reply #3 on:]

Sorry if the links didnt work for you. Here are some better ones of the
components I have here:

My phototransistors:
http://www.datasheetcatalog.org/datasheet/siemens/BP103BF-2.pdf
http://pdf1.alldatasheet.com/datasheet-pdf/view/143177/ETC1/BPW42.html

My IR LED:
http://www.datasheetcatalog.org/datasheet/siemens/LD274.pdf
http://www.datasheetcatalog.org/datasheets/37/486544_DS.pdf


1. Is it possible to build a barrier sensor just with these components without external
ICs etc. (Of course resistors)?

2. Is it possible to modulate a beam just with eg. PWM of the arduino?
Could someone provide a very small code example just as a hint? It would be nice to read
the state of the IR barrier sensor as simple as this little sample:

Code:

if(digitalRead(IRSensorPin) == LOW){
       Serial.Print("Alarm!!!")
}

3.  The link you provided needed some other components too. Is it because the serial data
transfer (btw thats really cool... )? I just want to detect if the beam is disconnected
because of an object so can it be simpler?


Thanks you so much!

[Reply #4 on:]

Thanks for your input and help.

I will have closer look on the modules which allready send at
a certain modulation. Thanks for your advice!