Looking for DirecTV IR remote decoder improvement suggestions

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crhoc_2121991
Level 2
Level 2
First like received Welcome!

Hey Folks,

I'm working on my first real PSoC5 project (only done blinkie so far). I have a bunch of DirecTV RC65 remote controls and want to decode the IR signal in hardware. I've done this a lot with Arduino software decoder library. The RC65 in factory mode uses variable length bits for mark and space. I found this

/*

* According to http://www.hifi-remote.com/johnsfine/DecodeIR.html#DirecTV

* The IRP notation for this protocol is:

*{38k,600,msb}<1,-1|1,-2|2,-1|2,-2>(5,(5,-2,D:4,F:8,C:4,1,-50)+) {C=7*(F:2:6)+5*(F:2:4)+3*(F:2:2)+(F:2)}

* Unlike most protocols which use a fixed length mark and a variable length or a variable length

* mark a fixed length space, this protocol varies both the mark and the space.

* The stream is still a series of marks and spaces but the length of either of those

* denotes a one or zero. A length of 1200us=logical 1 and length 600us=logical 0

* It also makes changes to the length of the header mark to devote repeat codes.

* The first header mark should be 6000us but repeat codes should only be 3000us.

*/

And I'm seeing variable length 1/0's on my bench. Here's my schematic, an analyzer capture showing the IR bit stream and my debugging digital outputs. Also attached my project.

DirecTVDecoder.cysch.png

I'm looking for suggestions and improvements to my first PSoC design.

Thanks for your time.

Craig

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1 Solution

Hello Craig,

You can use the UDB counter with an enable input. Right click on the counter component, and select "UDB" for the "Implementation" parameter.

CounterUDB.png

The counter will now count on the rising edge of the "count" input.

CounterWithCountInput.png

Incidentally, I had referred the same book you mentioned, at college in the year 1983.

Thanks, and regards,

Sampath

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4 Replies
SampathS_11
Moderator
Moderator
Moderator
250 sign-ins 250 solutions authored 5 questions asked

Hello Craig,

Your first PSoC design is extremely impressive. We have faint hope that we will be able to suggest any improvements to your design without doing a thorough study first. Kindly do excuse us, since this will be taking us an unspecified time, but surely we will evaluate and give you feedback about your design.

Thanks, and regards,

Sampath Selvaraj

Apps Engr Sr Staff

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Sampath,

Thanks for the compliment. I had a lot of fun playing with Creator and my $10 059 kit. I hadn't really done digital design at this level since I was a college freshman in 1981, back then we used a wire wrap tool and this, The TTL Data Book for Design Engineers: Amazon.com: Books . Ha!

Without putting in significant time, can you answer this? My design uses a duration timer to generate an interrupt after all bits arrive. All packets have same bit count, I'd tried using a simple reloadable countdown counter for this but simple counters can't use asynchronous clock signals for their clock input. I worked on this with all counters and couldn't get a counter solution to function, so I just used a duration timer which works but its kind of a hack. You have any suggestions here?

Thanks for the view and the comment.

Craig

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Hello Craig,

You can use the UDB counter with an enable input. Right click on the counter component, and select "UDB" for the "Implementation" parameter.

CounterUDB.png

The counter will now count on the rising edge of the "count" input.

CounterWithCountInput.png

Incidentally, I had referred the same book you mentioned, at college in the year 1983.

Thanks, and regards,

Sampath

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Sampath,

Thanks I'll try this and compare hardware utilizations.

BTW, I just added this project to my github account if anyone is interested, https://github.com/holla2040/psoc5DirectvRC65IRReceiver

GitHub - holla2040/psoc5DirectvRC65IRReceiver: A PSoC5 hardware-only IR decoder for DirecTV RC65 rem...

Craig

ps. I think all EEs in the 80s had the TI Data Book. Mine is somewhere around here....

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