Mauricio Jancic wrote:

> - the 1st thing says that the start sequence is a TX of 2400 uS and a NOTX
> of 600uS. Then, a 0 y 600 TX + 600 NOTX while a 1 is 1200 TX and 600 NOTX

Correct.

> - the second thing says the start is ONLY the 2400 uS TX pulse and the
> immediately starts the sequence. 0 is 600 NOTX + 600 TX and 1 is 600 NOTX +
> 1200 TX....

Nope. Think of the interbit time as 600us.
The start bit is 2400+600. The width of the ON time determines if
you have a 0 or 1.

The URL I posted clearly shows this.
http://www.boehmel.de/sircs.htm

> If you take a look at the file I sent to the list, you'll see that the 1st
> "theory" is *incorrect" since the last bit is incomplete... If I recall
> right.

The last bit is NOTX for 600 then NOTX for the balance of the
45 msec to the next frame. Your file ends just as the last bit
is unasserting (goes high).

45 msec is frame rate, start bit to start bit, since the frame
length can vary from 3+ 12*1.2ms=17.4ms to 3 + 12*1.8ms =24.6ms

Remember that IR is LOW assert on most detectors, so your PIC
waveform is inverted from what it needs to be if that is
what you are using to drive the base of your transistor.
No wonder you're having trouble...

Robert

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