Salve Richard! Robert Michel schrieb am Dienstag, den 12. Dezember 2006 um 17:58h: > > I'm not an audio engineerologist, however a quick read of the > > datasheet shows input/output rates of up to 96kHz.. so the theoretical > > highest frequency at that level would be 48kHz.. meaning there may be > > room in the non-audible spectrum for comms depending upon the > > sensitivity of the mic/speaker components. > :)) > Doing distance messuring with ultrasonic? > ;)) > 40kHz example: > http://www.parallax.com/dl/docs/prod/audiovis/Distance28015.pdf
BTW 40kHz, there is a time signal radio in Japan broadcasting on 40kHz: http://en.wikipedia.org/wiki/JJY Just adding a magnetical loop into audio in and use it for receiving the lowest part of LF and VLF - ok -this isn't yet a "killer application" but it would be educational to play with that, and someone in Japan could be happe to have beside GPS a backup for a time signal. Military Neos could have a build in VLF loop so that some informations are received on this way: http://en.wikipedia.org/wiki/Very_low_frequency And maybe next generations of audio ICs would have an ADC with a much higher frequency range for low cost LF receiving? (I know that this would not be not so battery efficient like a hardware receiver, but probably cheaper) Just a magnetical loop and a frequency that is broacast free will make a fine lightning detector I don't know if 2 channels are enough to track the distance of lightning, I once saw a page with a 3 channel detector - but it could be that the 3 channel is only needed to know the side of the lightning (2 channels = non unique solution ?) Maybe an I/O of the SoC could work as third AD. But multiple Neos in one city could be a solution to do this with a distributed system - the accurate time and position with AGPS helps: http://www.engr.uconn.edu/ZEUS/publications/al02.pdf (But consider that you would share your position as well) (Such a distributed detector system could work with audio as well (in open fields) - try to detec where a bang/noice came from) So when the Neo1973 case would have a build in simple magnetic loop switchable to one audio in, it could become possible to use the Neo1973 for tracking lightning :) OKOKOK audio in connector would be good enough to play with this and the idea of an internal magnetic loop antenna switchable to one audio-in would be for the Neo v2. The distributed system could share lightning events via GPRS or (future: Bluetooth, Wi-Fi, packet radio via PMR/DMR). Richard, you are right, the 96Khz range of the ADC give some new playfield... :) Greetings, rob PS: and ultrasonic cold maybe used for some material scan (to detec hollow space or fractures..) _______________________________________________ OpenMoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
