• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

InfraRed Analog Tranciever

Status
Not open for further replies.

stevo99

New Member
Hi,

I am designing an InfraRed link to tx and rx an analog signal over a distance of about 5m.

Can anyone offer any pointers to cct diagrams or other resources I may use as a starting point for this project

Thanks

Stevo
 

Nigel Goodwin

Super Moderator
Most Helpful Member
stevo99 said:
Hi,

I am designing an InfraRed link to tx and rx an analog signal over a distance of about 5m.

Can anyone offer any pointers to cct diagrams or other resources I may use as a starting point for this project

Thanks

Stevo
What sort of analogue signal?.

Do you just mean a voltage reading?, or something like an audio signal? - and if so, what sort of bandwidth do you require?.
 

Gandledorf

New Member
Nigel Goodwin said:
stevo99 said:
Hi,

I am designing an InfraRed link to tx and rx an analog signal over a distance of about 5m.

Can anyone offer any pointers to cct diagrams or other resources I may use as a starting point for this project

Thanks

Stevo
What sort of analogue signal?.

Do you just mean a voltage reading?, or something like an audio signal? - and if so, what sort of bandwidth do you require?.
I'm actually working on several similar systems, and over the weekend will be working out the details on a quad-opamp band-pass filter. I'll post my results by Monday, so hopefully they will be of use to you.
 

stevo99

New Member
Nigel Goodwin said:
stevo99 said:
Hi,

I am designing an InfraRed link to tx and rx an analog signal over a distance of about 5m.

Can anyone offer any pointers to cct diagrams or other resources I may use as a starting point for this project

Thanks

Stevo
What sort of analogue signal?.

Do you just mean a voltage reading?, or something like an audio signal? - and if so, what sort of bandwidth do you require?.
Basically it is a 9600 Baud, full duplex data link and has a bitrate of about 57K6bps. Using fdm There are 2 distinct frequency bands 1 for tx and 1 for rx which I can filter easy enough. I was wondering if anyone else has done something similar.

Stevo
 

Nigel Goodwin

Super Moderator
Most Helpful Member
stevo99 said:
Basically it is a 9600 Baud, full duplex data link and has a bitrate of about 57K6bps. Using fdm There are 2 distinct frequency bands 1 for tx and 1 for rx which I can filter easy enough. I was wondering if anyone else has done something similar.
Well that's a digital signal - not an analogue one :lol:

I'm also a little confused about your speeds? - 9600Baud is usually 9600bps, assuming normal 8N1 type protocols. Or is the vastly increased bps because of error correction added to the data?.

'Normal' IR remote controls work nowhere near that fast, usually only about 2400 or 1200 baud, and you can't normally just send standard serial data across them - you need some kind of coding, Manchester coding is commonly used.
 

stevo99

New Member
Nigel Goodwin said:
Well that's a digital signal - not an analogue one :lol:

I'm also a little confused about your speeds? - 9600Baud is usually 9600bps, assuming normal 8N1 type protocols. Or is the vastly increased bps because of error correction added to the data?.
Sorry if I am a little vague. There are some sensitivities surround a project I am working on so I'm trying to be as general as possible.
Yes you are correct, what I described was a digital signal, however due to the encoding and modulation mechanism it is presented to layer 1 as an analog signal.

My original question probably should have been "What is the bandwidth of an IR link? Can anyone give me some pointers to good resources I can look up on the subject." 8)

Regards

Stevo
 

Itay Reiss

New Member
Try this website for help on remote control applications

A good website for designig remote control applications would be:

www.rentron.com

You can contact their technical support for any question you have, there is a guy called Bruce, who is a calibre in this field. :!:

I myself used the information there to design a Rx, Tx IR system from scratch.

Itay
 

pebe

Member
Basically it is a 9600 Baud, full duplex data link and has a bitrate of about 57K6bps. Using fdm There are 2 distinct frequency bands 1 for tx and 1 for rx which I can filter easy enough. I was wondering if anyone else has done something similar.
I don't understand why you need two frequecies. For 1 tx + 1 rx you need two beams, so you can use the same frequencies - just switch off the rx each end when you are txing from there to stop 'splatter'.

As Nigel said, you ideally need Manchester coding, but if you can ensure correct signal polarity at the receiver, then you can use baseband signals with normal start and stop bits.
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top