Re: Handyboard Expansion Sonar Issues Look at these: http://el.www.media.mit.edu/projects/handy-board/software/sonar.html     and  http://el.www.media.mit.edu/projects/handy-board/hbexp30/software.html I also added a 100uF cap across the supply as shown in this link: http://www.robotics.com/arobot/sonar.html Others suggest ana even larger cap. (470uF), but I haven't had any problems with power sag until the batteries are almost discharged.  - - - Nick - - - "Terry P. Gathright" wrote: >  > Hello, > Where do I look for the directions for connecting the Polaroid sonar to the > expansion board. >  >  in the directions?   > >                                         Thanks >                                         Terry G. >  > ---------- > > From: William Bain  > > To: handyboard@media.mit.edu > > Subject: Re: Handyboard Expansion Sonar Issues > > Date: Friday, February 05, 1999 12:57 PM > > > > On Fri, 5 Feb 1999, Nick Taylor wrote: > > > > > jdunn@unm.edu wrote: > > > >  > > > > There is a very high probability that you plugged the foil cable in > > > > backwards.  Doing so, even for a moment, will destroy the IC chips. > > > > > > Please explain.  Now I'm worried about damaging my sonar board.  Since > > > the foil cable has conductors on only one side, I didn't think that it > > > was possible to plug it in "backwards" and still make an electrical > > > connection. > > > > > > My understanding of the hookup is as follows: > > > On the HB Expansion Board pin 1 (gnd) of the Polaroid connector is > > > toward the top of the board.  On the Polaroid Ranging Module pin 1 > > > is toward the left.  If the foil cable is connected so that the > > > dotted edge of the cable is nearest the pin 1 end of each connector, > > > I fail to see how there is any danger of damaging the sonar board. > > > > It's possible that the flat flex cable could make electrical contact > > either way, since the socket has "teeth" in it that could penetrate the > > insulation on the one side of the cable. > > > > And *don't* trust that the dotted edge is the correct one; I ordered the > > pair of sonar kits, and it came with one cable correctly marked and the > > other cable incorrectly marked. > > > > Just make sure that pin 1 as marked on the sonar module board ends up > > connected to the corresponding pin on the expansion board.  If you're in > > any doubt, check the circuits and verify that V+ goes to V+, GND goes to > > GND, etc.  I hope this helps. > > > > --Will > > > >