USART and IR ??

[SystemFailure]

Hello,

This is my first post, I hope someone will help me

I'm using PIC 16F877A, and I wish to create IR Send/Recieve, something like a mini remote control.

They will transmit one byte only, just a signal.

I'm thinking about using the USART functions mentioned in the manual, but I really don't know
how the connections would be.

I attached the connections example mentioned in the MikroC manual.

Any Suggestions?

 

[Wilksey]

Hi.

First of all, the image you posted is for PC Serial to PIC UART communication.

Secondly, for IR communications you need a infrared receiver LED, and infrared transmitter LED, and I think, someone correct me if i am wrong, you need to generate a 32khz? carrier signal.

You may be able to do IR comms with ADC to receive and maybe transmit with PWM?

Unless you are trying to do something else?

Wilksey

 

[AtomSoft]

You are corrected in the fact thats its just UART.... IR can be a different signals like:

36khz, 38khz, 40khz etc.... Depending on the Protocol....You would need a IR Receiver specifically made for the carrier signal. So if you use SONY IR (SIRC):
SB-Projects: IR remote control: SIRC protocol

You would need a 40Khz Receiver to get the data... You can create a custom Protocol but then you will most likely get none to little help. The link above contains a ton of info... and here also:
SB-Projects: IR remote control

 

[Wilksey]

I stand corrected, I have never done any IR comms personally, I have only used PIR's for triggers.

So, AtomSoft, is 40KHz a "standard" carrier signal? Is this what a universal remote control would use? I presume a 40KHz would not also be able to read a 38 or 36 for example you would need a matching carrier signal tx and rx?

Regards,

Wilksey

 

[Nigel Goodwin]

The exact carrier frequency makes very little difference, I usually aim for around 38KHz, which then works fine with 36, 38, and 40KHz receivers. Details of Sony SIRC's and doing it using PIC's are in my tutorials.

 

[AtomSoft]

You have to remember the difference between a Receiver and a Remote (transmitter) The Remote can do all those signals because its just using a IR LED and the Carrier is CODED into the IC. The Program tell triggers the LED at the RATE needed producing the IR SIGNAL. The receiver is the specific part. The remote can be any IR transmission i think heh...

EDIT:

Nigel Tutorials are where i learned my first IR from so be sure to check it out. Its in ASM if i remember but it shows great info there...