On Sunday 21 September 2008, Charles Pax wrote: > On Sat, Sep 20, 2008 at 8:42 PM, Al Johnson > > <[EMAIL PROTECTED]>wrote: > > You probably want to look at these two. The main limitation is that > > you've only got one input channel via the jack, but you might be able to > > get round that using the mic switch detection. > > I incorrectly assumed there is stereo input on the jack. I'll have to go > back and rethink this whole thing. What is the mic detection switch?
There's a switch on the headset that shorts the mic when pressed. I've not looked into how this appears on the freerunner. > Can I > record audio from the mic input and the built-in microphone at the same > time? Yes. Route headset (mic1) to the left ADC and handset (mic2) to the right ADC, then set the record mode to stereo. > > Since you need external bits for the IR anyway you may be better off > > making a > > USB device instead. The arduino and other similar devices make the USB > > part relatively easy. Put a narrow bandpass filter on your audio > > transducer and you make the audio signal a simple on/off - use multiple > > frequencies if you need to track different markers or indicate different > > states. > > I'm hoping to find some novel way of doing this with the most simple > hardware setup possible. Maybe we can have each transducer connected to a > bandpass filter that activates an oscillator. If the two oscillators > operate at different frequencies on the same mic-in channel, we should be > able to process this in software on the Freerunner to calculate when each > oscillator was triggered. This would allow us to use only dumb and cheap > hardware that should work on any computer with a mic-in. The IR detector(s) > can also be connected to a oscillator operating at a third frequency. Sounds more complicated than making a usb device to me :-) > What do you mean by "external bits for the IR"? Data bits or just little > pieces of hardware? I figure a photodiode can be connected between signal > and ground. When suficient IR light hit it the diode should make a spike on > the mic-in channel. Bits as in components. I've not tried a photodiode on a mic input, but it sounds like the sort of thing someone might have done for lirc hardware. > -Charles Pax _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community