[Voyage-linux] Newbie question about initial Voyage install.

[Nick L.]

On Wed, Nov 18, 2009 at 11:51 PM, jack makrl <jack.makrl at gmail.com> wrote:
> To clarify my last message, I tried using this serial port ir receiver:
> http://www.irblaster.info/receiver.html
> w/ my alix3c3 but it didn't work. Turns out it needs handshaking signals.
>
> USB ir receiver works well. I'm really pleased w/ the alix as a mpd
> device. It's been up for 403 days. I need to get around to figuring
> out how to integrate the picoLCD-4x20 I bought over a year ago to
> complete the project.

I emailed PC Engines about suggestions and help with on the Alix. His replies:

"COM2 should be functional, but uses 3.3V levels, not RS-232. You either
need to add an RS-232 transceiver, or bypass the RS-232 buffer on the
IR receiver board."

And...

"Doing software decoding of IR is really bad for CPU load, and will
break easily when system
load is high. I don't think it is a good idea to put this kind of
real-time requirements on your
system.

My suggestion: use a small "disposable" microcontroller (e.g. PIC,
AVR, whatever)
to decode the IR, and send the data to your system through the serial
port. From there you can
pick up the data at your leisure using a normal serial port driver.

You can even get a 32 bit microcontroller for less than a buck these
days (see new intro by NXP, that is volume price of course).

See e.g. http://www.best-microcontroller-projects.com/infrared-receiver.html
for a starting point.
Probably many others around. Try to google "infrared receiver microcontroller"."

That link is a bit more DIY than I would like; involves programming a PIC.

I did find this: http://www.infraredremote.com/8pindecoder.htm

And Pascal's response: Yes, this should be able to connect directly.

So, a small pre programmed PIC that can decode IR and send serial data
out at 3.3 volt levels -- if I understand all this correctly.

Jack,

I'm assuming your USB IR receiver does not have a decoder and your
Alix CPU is doing the decoding in real time? Did you happen to look at
how high your CPU load gets when decoding IR?

Anybody on list know of an off the shelf and assembled IR decoder that
has 3.3 volt serial out?