Hi Mike, I'll answer the questions in line with your email message, below...
On Sat, Oct 11, 2008 at 12:40 AM, Mike Monett <[EMAIL PROTECTED]> wrote: > "Robert Darlington" <[EMAIL PROTECTED]> wrote: > > > I use them for non-time keeping things. You need to use the > > configuration tool to configure the ports so that they both spit > > out NMEA, and the particular NMEA strings you want to see, and > > then save the configuration. > > > Otherwise you get NMEA out of one port and the Trimble binary > > format out of the other. Do you have a copy of the software? You > > can find it here: > > >http://www.trimble.com/embeddedsystems/lasseniq.aspx?dtID=support > > > Also, make sure you have the IQ and not the SQ. The SQ only has > > one port but is otherwise pin compatible. > > Robert, > > These units look interesting. Do you mind if I ask some questions? > > 1. What kind of non-time keeping uses have you found for them? The first project was an APRS beacon for a high altitude balloon project which hasn't launched yet, but was tested in my car. The last project was for the local laboratory. They developed a sampling system which had every gadget but the kitchen sink in it, and every part was made out of unobtanium. In this case the gps board had been discontinued for about 4 years so I had to design a new one that would be the same physical size, same hole spacing, and same pinout. I figured if I was going to do this and have a minimum run of 5 boards, I was going to make 2 for me (they needed 3 total). In the picture you'll see the top half with the GPS module has a white box around it. This part I cut off after programming the GPS receiver modules and installed in their gadget, the rest of the board gave me a MAX232 (3.3 volt version if I remember right) and broke out both serial ports to DB9 for easy hookup to a PC. I should've added a PPS line but was too concerned with keeping the board working when I cut it in half to really think about more than what they needed. What you can't see is the button cell battery on the back for retaining constellation data Here's the board: http://www.losalamostech.com/gps_board.jpg Here's their gadget: http://www.*lanl* .gov/orgs/tt/pdf/techs/hands_off_gun.pdf > 2. How well do they work indoors? Do you have to be near a window? > What about inside a multi-story building? We only tried it outside. Their gadget got the short little ceramic patch antenna. I used the longer (5 meter I think) mag mount version in my car when testing the APRS beacon. > > > 3. How well do they handle constellation changes? Is there an abrupt > shift in position? > No clue! Sorry. > > 4. Have you ever taken the shield off and looked inside? If so, can > you see the crystal oscillator and tell whether it is a bare crystal > or a complete oscillator module? > No, but it comes off easy enough when not soldered down. I'll try to pop mine open and take some pictures of the guts for you later today. > > 5. How much do they cost? Do you know of any others that are > cheaper? > We paid somewhere on the order of $50 + the antenna. Sparkfun sells them here for $56: http://www.sparkfun.com/commerce/product_info.php?products_id=163 They also sell the antennas and breakout boards that already have the tiny little surface mount sockets (I have a few left if you end up buying one of these). The really interesting thing is that the manual states that the PPS output is within 50ns of reality. I plan on using one to discipline that Efratom rubidium standard I was asking about earlier in the week. By the way, the connector from Mouser electronics came in and I'm ready to go, just waiting on the part to come in from China. -Bob > > Thanks for your help! > > Best Regards, > > Mike Monett > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
