Serial communincation between two Microcontroller using IR

Decrease cost ? Well, you need to design a decent receiver first.

Rene

Digi-key has logic output IR receivers for $1.08

That will simplify things considerably though you will have to modulate the transmit end but it is not at all difficult.

GG

and that decent reciever can be built using opams like lm324

is it necessarry to modulate the signal cann't we send it as ASK or OOK signal

You wont get much range unless you use a modulated signal. The modulation and the coding can all be done in software...

This is how I did my 2-way IR link.

Luhan

Oh, can it ? At what speed for what baud rate ? With a fixed gain ?

Rene

Please define cost.

Get the modules from Radio Shack. ;-)

Good Luck! Rich

Those recievers go for about $4 in the little metal can. They are VCR leftovers. The TSOP4838 from digikey is about $1 and fits in a smaller space.

Luhan "El Cheapo" Monat

With a modulated signal (typically around 40 KHz) from the sender and a bandpass filter for the same modulation frequency on the receiver then you can be relatively immune from spurious signals, particularly big DC signals like sunlight or even incandescent bulbs.

An outgoing signal is easy to modulate. On the receiver side, you'll have to run the numbers to see whether it's more cost effective to spend non-recurring engineering costs in designing your own receiver or to just buy a canned module.

If it's for self/class/curiousity, then a build-it-yourself would be a fun project. If for a commercial product, much harder to justify. There may also be patent issues involved in a new design where, presumably, royalties and rights for commercial use would already be part of the price of an off-the-shelf unit.

I have got some IR reciever module from the local market costing 0.4$ it is like TSOP1738 module,

Total cost should be of project should be less then 5$

Hi,

I've done a similar project where I used two pic16f628 to communicate using rs-232 over infrared. I've posted some messages on this yahoo group:

Search for IR and rs-232. I've got a design at home, which I can send to you.

Greet> Total cost should be of project should be less then 5$

I have designed the same using 89c2051 controller and its working fine.

now I am planning for RF.