Home-Brew IR port. Was - Please Ignore RS232 message. The subject should read IrDA port... Sorry

Alan Ide gamebeavis at gmail.com
Fri May 11 18:21:31 CEST 2007

The IR transmitter I found on LIRC is a home-brew transmitter that is simply
a serial port device. So if my understanding is correct, LIRC is simply
sending data at the baud rate of the serial port (19.2 I think) and the data
itself is modulated to get the desired effect. Thus, we arent taxing the
driver or the hardware at all, it is simply a one way serial communications
data stream. As long as we can configure one of the GPIO pins as a serial
communications port (via the driver interface), this should all work just as
planed. So either we need an unused serial port, or we need to configure one
of the GPIO pins to be the TX of a serial port, and we have a functioning

Thank you for your ideas, every idea helps.

On 5/11/07, Paulo Marques <pmarques at grupopie.com> wrote:
> Alan Ide wrote:
> > Ok, I have formulated a plan of attack for my IR port addition. I have
> > been googleing (is that a word?) my little brains out for 2 days now and
> > this is what I have come up with thus far. I was looking for the
> > simplest (no sense in reinventing the wheel) but also the most
> > "customizable" solutions. Please note, this is my first such attempt at
> > a "hardware" project, my "hack" skills lie mostly in higher level
> > software, thus I NEVER before had to interface with hardware directly,
> > so this could all be WAY off. Please be brutal with your opinions.
> Ok, you asked for it ;)
> What you're trying to achieve will be really difficult by just
> connecting a led to a GPIO.
> IIRC, an IR remote usually modulates the signal to avoid interference,
> so you'll probably have to toggle the IR pin at frequencies of around
> 36kHz which will put very hard real time constraints on the driver.
> A completely different approach, that I though of while reading your
> post, is to have a bluetooth receiver with an infrared emitter attached
> and use it as a bridge between the Neo and the devices you want to
> control.
> The advantages are:
>   - you don't have to hack your Neo, no risk of damaging it
>   - the bridge box can be "big" and use standard size components which
> make it easier to build
>   - you don't have to point your Neo at the receiver
> On a quick googling I found these (but there are probably others):
> http://www.ipenabled.com/firefly.html
> http://www.innotechsystems.com/sp4001.htm
> Used together they can probably do what you want to achieve, but I would
> have to read the specs to make sure (baud rates, protocol, etc.)
> Maybe googling some more, we will find a device already made for this...
> Just my 0.02 euros,  ;)
> --
> Paulo Marques
> Software Development Department - Grupo PIE, S.A.
> Phone: +351 252 290600, Fax: +351 252 290601
> Web: www.grupopie.com
> "God is love. Love is blind. Ray Charles is blind. Ray Charles is God."
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.openmoko.org/pipermail/openmoko-devel/attachments/20070511/b9a77bb7/attachment.htm

More information about the openmoko-devel mailing list