Re:  See www-personal.engin.umich.edu/~johannb/  for a detailed paper on EERUF (Error Eliminating Rapid Ultrasonic Firing). Using the algorithm described there, he used 12 sonar sensor at the same time - allthough I don't know if the HB is powerfull enough for it... Jeroen van der Vegt. -----Original Message----- From: Elliot Anderson  To: handyboard@media.mit.edu  Date: zaterdag 20 februari 1999 21:42 > Has anyone connected more than one sonar sensor to the handyboard?  I'm >looking to use the handyboard to connect six sonar sensors to my pc via the >parallel port.  I'm using C to talk to and readback from the parallel port. > The sensors can be fired and read in sequence, as long as they can be >fired and read back quickly. > I'm using the sensors to grid out a room in order to locate people in a >space and track their movements.  The space is typically about 12' long. >I'm not a hardware expert, but am somewhat adept at building circuits. >Therefore, as much detail on how to handle and build this interface would >be helpful. > >Thanks, >Elliot Anderson > >Elliot Anderson >Adjunct Professor, Electronic Media, >Art Department >University of California, Santa Cruz > >http://www.sirius.com/~ewanders >