IR Booster Pack

[gordon 229]

Here's a little Payload (yeah, let's add some more confusion ) for IR communications. It's basically completely oPossum's EHP TV-B-Gone design for the transmitter part, and also oPossum's IR Widget for the receiver parts. You may think of it as Dangerous Prototypes' USB IR Toy for the LaunchPad, but with more oomph.

 

There's a healthy list of compile-time configurability and features:

 

1. 
   [*:22nw21ko]selectable transmitter power source (LP's VCC or external)
   [*:22nw21ko]FTDI cable-compatible RX/TX breakout for the capturing sessions when 9k6 is not enough, selectable for both pre-'2553 and '2553-style RX/TX pinout
   [*:22nw21ko]IR demodulator for your remote
   [*:22nw21ko]IR photodiode for capturing your unknown remote's codes
   [*:22nw21ko]five transmitter blocks (wire in as few or as many as you actually need)
   [*:22nw21ko]all of these are functions are wired to pins where they make most sense
   [*:22nw21ko]unused pins brought out to a tiny bit of a prototyping area so you can do

this properly right on the board
[*:22nw21ko]all of this in 1206 so you can build it even if your kit is a copper rod and a BBQ fireplace

 

Software-wise there's nothing overly usable yet, but the CIR capture thread and the IR Widget writeup is more or less what one needs to get going.

 

A big "thank you" to oPossum is quite in order; he has been invaluable help. Thank you!

 

 

I am now seeking input as to what else might be there you'd like added (though I want to keep it IR-only, and it's pretty good at that , or anything else you may want to add. I'll keep this afloat for a couple of days, then replace these design files with the final ones.(The Eagle files will come soon, when Bluehash allows .sch/.brd attachments :mrgreen: )

ir8.sch

ir8.brd

[bluehash 1,581]

I like it. What do you mean by a transmitter block?

[gordon 229]

Thanks.

 

A transmitter block is one IR LED and its amplifier stage:

 

 

(The Eagle schematic has the full shebang. On the above images only one is shown as the rest are just repetitions and not needed to show the guts of the thing.)

 

If you want to use it as an IR light saber, you just wire it up all five of them and start slashing tusken raiders. If your use case is, say, the above-linked AC remote control, you'll probably get by using one or maybe two transmitters, so you just simply don't wire the others up, saving battery. You may still want to wire up the demod (or the photodiode) so you can remotely control the remote control, making it independent of a PC (serial terminal) but still being able to, say, choose between cooling profiles or whatever else you can think of but the AC won't provide. Or, you can have one suitably-powered and strategically placed unit controlling appliances/lightning in your home so as to make it appear you are there, thus deterring the burglar while you are away -- this may well need all the transmitters, in contrast to using it as a simple IR remote receiver for your HTPC, which will need about zero of them.

[gordon 229]

So Booster Pack it is RIP Payload.

 

Slight mods in this version. Gave up on trying to be the universal, so it's ultimately geared towards the '2553 now, but -- giving up on certain features or having to do certain things the hard way -- works down to 10-pin ones as well (I think ).

 

This is highly likely to be the final version.

[gwdeveloper 275]

Very cool! I want one already.

[gordon 229]

Boards have arrived, one has been assembled.

 

Functionally it's quite fine, all three functions (transmitter, decoder, demodulator) work as expected. There are three problems left:

1. 
   [*:3fe7np1b]At (1), RX and TX are reversed. Slightly inconvenient as one can not plug an FTDI cable directly as intended, but some cable juggling is needed.
   [*:3fe7np1b]At (2), the silk should read XMIT; bad copy-o.
   [*:3fe7np1b]The silk is pretty bad in general. I made almost all the texts too small, so most of the them (especially labels on the proto area) are quite unreadable and resemble small amorphous blobs.

Apart from these issues, it turned out quite nice. Notice the obligatory green wire in stylish red (lifted a pad... need to re-think or learn to use solder pad jumpers).

Attached to this post are the Eagle files. As the issues remaining are more cosmetic than showstopper ones (the UART mixup can easily be fixed on the proto area), I am unlikely to pursue fixing them too actively.

 

Have some made and enjoy!

 

A word of warning: calculate the power requirements of the IR LEDs carefully (especially if you plan to use high power ones), and use external power for the LEDs if necessary. The LaunchPad LDO can supply only so much current without tripping over; 5x1A even in bursts only is way over its limits.

IRBP.zip

[MattTheGeek 99]

gordon,

 

Whats the trace width of your external power? I believe you might be exceeding the maximum current limits for your power traces. Also try to add a extra via when you are switching layers, as one via might not cut it.

 

Regards,

Matthew

[gordon 229]

I think it's 24 mils.

 

Good catch, though, I absolutely had not given this any thought whatsoever.

 

Thanks for your tips, much appreciated. I'm re-doing some of the layout (some things have not worked out very well), these will be considered as well.