Topic: I want headphone and mic ports

Here is the situation, my girlfiend and I like to spend time time near each other but not necessary doing anything togather. She like to listen to audio books while she does her sokudo. Currenly she uses the oldie Ipod for this. What would be better if she could just stream the audio books from her PC via a Chumby with a headphone port. Headphones here help keep the noise level down.

I am not so sure what to do with a mic. One idea is a Chumby-to-Chumby intercom.

Re: I want headphone and mic ports

The chumby already has a headphone jack in addition to the built-in speakers.  The current chumby does *not* have a microphone, but I believe the chumbilical has a line for it.

Re: I want headphone and mic ports

i planned to add a microphone input. only realistic ideas for it so far are for using it to recognise claps for turning the alarm off.

need upload space for the forums or a chumby blog? right here then
http://www.nophus.com/useru
username is chumby
password is chumby

Re: I want headphone and mic ports

Ports are a metaphor demarcation to me. That's to say the usage intentions can be both constrained or enhanced.
One also needs to consider factors of design interactions. A simple enough in concept "headphone jack" adds complexities of switching internal to external audio. Then impedance matching between internal speakers and whatever gets plugged in to the jack.Let's also consider ground loop/stray voltage issues. Even if  most of these have already been solved by "prior art". Even then- safety certifications and RF compliance factors become often nasty bugbears. Look back to the " All-American-5" tube radio of transformerless design for details in how they were handled.

As for a microphone port- could an internal microphone suffice? If so- let me resurrect a techhack from long ago.

The concepts below that are not exempt as prior art, are donated to the Chumby Project under copyleft save only for my hope that someday they may earn me a Chumby incorporating them - as honorarium.

Dynamic Speakers CAN be used as MICROPHONES!

Route the audio thru some switching or path isolation stunt- Possibly even using the audio out amp as an audio IN amp. All it takes is some logic driven switching . Left open for further discussion is interactivity potential so created.

Oren Beck

5 (edited by MrBimmer 2007-01-03 14:34:00)

Re: I want headphone and mic ports

I think an internal mic would be best for both simplicity and design, something the end user does not have to buy or mess with, it just works.  As both my roomie and I plan on getting Chumb's, an intercom system would be quite nice (and I would be willing to help develop on it for sure if there is going to be a mic).

Re: I want headphone and mic ports

Could someone please explain how to tap into the mic chumbilical wire?

Re: I want headphone and mic ports

The mic line has all the biasing circuitry internal so you *should* be able to connect a standard electret microphone between the mic on the chumbilical wire and the AGND wire. Of course, this hasn't been extensively tested...

On the production chumby, you may find it interesting to note that there *will* be a microphone built into the chumby. This one will be tested. smile Thanks for all the feedback!

7BAA 2E53 01C1 DCFF 497B  E7F0 9699 A303 78F0 D9B9

Re: I want headphone and mic ports

Ooooh...does this mean that I might be able to leave a message on Chumby that someone else could listen to when they get home??? Nice. smile

Imagine how much money I could save on Post-it Notes...over a year or two...definitely enough to justify purchasing a second chumby....

Re: I want headphone and mic ports

Yeah, that was one of the applications I had in mind, a vocal "To-do list".

And is there a way to get at the daughtercard without tearing up the casing? I wanted to put it there rather than the main board as it would be easier.
And how would you access it via Flash? What would be the ASnative number?

Re: I want headphone and mic ports

Unfortunately, the microphone is not supported in FlashLite 2 - I guess the mobile operators for whom FlashLite was originally developed weren't keen on having it be able to do voice recording and transfer.

At the moment, to use the mic, you'd have to write your own software.

Re: I want headphone and mic ports

zachninme wrote:

And is there a way to get at the daughtercard without tearing up the casing?

You should be able to open the velcro/hook and loop, pull out the beanbag and stuffing, then reach in and unscrew the daughtercard casing. The fabric is just sandwiched between two layers of hard plastic that form the back and front of the daughtercard case.

I have my chumby in pieces most of the time. I have pulled it apart and put it back together dozens of times and I've caused no damage, although I imagine the screw threads may wear out over time.

12 (edited by orenbeck 2007-03-01 21:43:05)

Re: I want headphone and mic ports

RE: stripped or worn out threads on prototypes.

Metal threaded inserts do reduce that risk. Admittedly at some expanse.
An acceptable compromise is intentional beefing up of the plastic surrounding the screw holes so several oversizes of screws can be substituted as holes wear.
A variant is literally broaching or molding the thread cavities as SQUARES so the screws tapping themselves in inherently can recut threads. MY preferred spec is very coarse thread large diameter almost square threads known as "acme" threads.
But a real world "close to the desired result" part is an ordinary coarse thread drywall screw.

Re: I want headphone and mic ports

Maybe mine is different/defective, but when you open up the velcro, its just a stitched up cloth thing. Unless you unscrew it through the fabric...

Re: I want headphone and mic ports

Cut through the fabric, it's the reason the velcro is there (so you can take the guts out and put more guts in and still have a sealed Chumby).

The easiest way is to cut the stitches.

Re: I want headphone and mic ports

Ah, good to know.
Thanks :-)

16

Re: I want headphone and mic ports

When I first heard about this thing, my very first thought was that I wanted it to drive speakers for listening to Internet radio.  My second thought was that I wanted it to have an internal mic so I could make an intercom out of it.  My office is in the basement and my wife and daughter are frequently ont he second story - bellowing for me at the top of their lungs to pick up the phone or whatever.

I see it's linux based but I have to read more about the flash.  Is it possible to do a GUI without flash, or to make a UI that controls another background app (since flash won't support the mic)?

Re: I want headphone and mic ports

"Is it possible to do a GUI without flash, or to make a UI that controls another background app (since flash won't support the mic)?"

Absolutely, but it would be entirely unsupported by the company (so you'd be a the will of the developer of said application). I've built libcairo on Chumby and have done some simple remote drawing stuff (a small TCP program listens for drawing commands) but I've not found a way to effectively switch between the default widget toolkit and my toy (other than forcibly killing one and starting the other), but I'm sure even that can be taken care of rather nicely (maybe with a script of some kind to launch an application selector?).

It's a matter of just building the software for Chumby (which isn't easy, but is far from impossible). Otherwise it acts pretty much just like any other Linux box.

Re: I want headphone and mic ports

There are free embedded versions of GTK and Qt that are pretty easy to port to chumby, and there are also lightweight X servers.

19

Re: I want headphone and mic ports

Well maybe I'll have a look when I get a chumby, as I am a developer.  I would hate to forgo all the apps others have written.  I have recently done some flash work for the PC with the latest flash, and it's a remarkable powerful language, much like Java.  It also supports binary sockets, although only to the server it was loaded from. 

I suspect this is a different and less capable flash.

Re: I want headphone and mic ports

The production units will support the XMLSocket object, just like desktop Flash.  You can actually open sockets to any domain, as long as that domain grants permission using the crossdomain.xml file.

21

Re: I want headphone and mic ports

Duane wrote:

The production units will support the XMLSocket object, just like desktop Flash.  You can actually open sockets to any domain, as long as that domain grants permission using the crossdomain.xml file.

Oh, great!  I'll ask more dev questions in the dev forum.