Ray,
Do you also happen to know someone in the US keep those chips in stock? Or you have to send a order to Taiwan?
 
Funny N.
Au Group Electronics, New Bedford, MA, http://www.AuElectronics.com

----- Original Message ----
From: Ray Newman <list@microdesigns.biz>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
Sent: Sunday, April 13, 2008 9:43:56 PM
Subject: Re: [EE] 38kHz carrier burst for IR code transmit

Here is my schematic of my 4x8 IR transmitter.

http://www.hacs.com/4x8_ir_transmitter.pdf

based on:
http://www.hacs.com/PT2221.pdf
http://www.hacs.com/uPD6121.PDF

You don't need PWM

but you do need LF series for battery operation.

It really is a simple design, hardware and firmware.
You don't need to use the ACK led.
I used this to setup setup multi-level IR codes.
I could actually output
4x8x32x16 different ir codes.
Actual frequency was 39khz

Ray



On Sun, 13 Apr 2008 19:48:31 -0400, Ray Newman wrote:
> OOPS!
> I forgot to include links
>
> Princeton Technology Corp. also makes the same 38khz part: PT2221
> http://www.princeton.com.tw/webSite/downloadprocess/downloadfile.asp?m
> ydownload=PT2221_PT2222_2.pdf
>
> Here are my pdf files for both:
> http://www.hacs.com/PT2221.pdf
> http://www.hacs.com/uPD6121.PDF
>
> Ray
>
>
> On Sun, 13 Apr 2008 19:23:37 -0400, Ray Newman wrote:
>> I have designed several products based on PIC MCUs Elan's VSE100
>> http://web.archive.org/web/20040402041226/www.elanhomesystems.com/prod
>> ucts/volume/vse.asp IR transmitters timing info was based on
>> Plessy
>> SL490
>>
>> But I have done over 20 NDA IR transmitter projects using PIC MCUs
>> based on uPD1621 timing information
>>
>> Including my own product:
>> http://www.hacs.com/essall.php
>> (see IR transmitter lower left hand corner)
>>
>> 4mhz internal clock is good enough.
>>
>> Ray
>>
>>
>> On Sun, 13 Apr 2008 15:27:14 -0700 (PDT), Estevan wrote:
>>
>>> All,
>>>
>>> I am experimenting with a IR remote and would like be able to  
>>> transmit the IR codes using a PIC. I have been experimenting in
>>> my  spare time to no avail, I am using this page as a reference
>>> now:
>>>
>>> http://www.sbprojects.com/knowledge/it/nec.html
>>>
>>> After studying this page, I had my scope hooked up and after  
>>> spending more time then I should have, I realized that the
>>> signal
>>>  is transmitted with a 38kHz carrier burst. I am not sure about
>>>  
>>> where to start with this using a PIC. I understand the basics
>>> of  
>>> the protocol now, but does anyone know of any reference code or
>>>  
>>> projects that might be a good place to start? My first goal is
>>> to
>>>  be able to duplicate the IR codes coming out of the remote with
>>> a  PIC, I figure baby steps is a good idea.
>>>
>>> Thanks in advance!
>>>
>>> Best regards,
>>> Steve









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