Sounds, excuse the pun, like the mic level is cranked too high. Have you tried Mic.gainAdjust()?
And what were the TestAcousticRanging errors, maybe there's something simple to fix. I have no experience with this, however I need to implement a mobile location mechanism for my robots...one of these days. So any information sharing that you feel comfortable with would be appreciated. I'm planning something that is exactly reversed from your system, three stationary sounders with a number of independent mobile receivers using ultrasonic rather than the micasb buzzers (I think the position accuracy will be dependent on the wavelength of the sound, and I was hoping to have something that isn't incredibly annoying to humans in the same room...) MS Hrvoje Mestric wrote:
Hi all, Me and my colleagues from Faculty of Electrical Engineering and Computing in Zagreb, Croatia are currently working on a simple acoustic ranging localization project. We are working with MICA2 motes. We have one moving MICA2 mote which periodically transmits 4,3 KHz buzzes. Three static MICA2 motes positioned in the corners of a room receive those buzzes and record the time that this buzz needed to reach them. Using this time they calculate the current range to the moving mote and send this data to the base mote which is connected to the PC (serial port). Then on the PC, we use those 3 received ranges to locate the position of the moving mote in the room. It all sounds OK, but it doesn't work...When preparing for this project, we made a small test application on a MICA2 mote. The application triggers red LED on a mote (redToggle) every time it receives 4,3 KHz buzzer sound (MicInterrupt.toneDetected). When we have started this application on a mote, red LED started blinking even though no buzzes were generated at the time and it was absolutely quite in the room?! Is this some kind of a hardware failure or this 4,3KHz frequency is constantly around us so MICA2 mote detects it all the time? If this second option is true, then we need to do some sound sampling to determine when our mote really hears a buzzer, right? How can we see the implementation of this MicInterrupt.toneDetected event since it obviously doesn't do the job according to our needs? We have also tried to use Vanderbilt code in TinyOS (TestAcousticRanging) for this purpose but somehow we cannot compile it properly + it says it is designed for outdoor use and static motes... Sorry for a bunch of questions, but reply to either one of them will be greatly appreciated. Best regards, Hrvoje Mestric Faculty of Electrical Engineering and Computing (www.fer.hr) University of Zagreb, Croatia (www.unizg.hr) ------------------------------------------------------------------------ _______________________________________________ Tinyos-help mailing list [email protected] https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
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