Lassen SQ

From Bellman
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Overview

The SQ is a module slightly larger than a quarter which has pretty good specs. Low power and pretty good accuracy. The pin-compatible IQ is even better but I got this SQ from eBay awhile back so it's what I am playing with. If this is too much fun to handle I will get an IQ later.

Launch

I obtained a developer board with USB from SparkFun.com and I have plugged the SQ into the board and powered up by connecting a USB cable.

To get it going, I installed Windows 2000 drivers from Silicon Labs and am now running the iQ_Monitor.exe program which SparkFun has on their website. It's running on com port 8. iQ_Monitor is a dandy free program.

The other program iQ_Chat wants to talk on funny serial ports that I don't have -- com1 and com2. :-) I am running W2K in VMware right now.

iQ_Monitor

I am in my house right now and the Trimble antenna is in my window. I doubt it has a good view! The Magnavox (with the antenna on the roof sees these satellites: 01,02,04,13,16,20,23,24,27

Here is a screen shot of the program right now.

IQ Monitor.jpg

In the time it took me to capture, edit and upload this image, the SQ has locked onto 2 satellites. It has a bad view of the sky right now, poor thing.

I used the program to upload an a GPS Almanac into the module.

I need to get a 12mm battery for the developer board to keep the almanac around when the computer is powered down. Might have one lying about somewhere.

I put the antenna outside (it comes with a long antenna cable!) and I've got a 3D fix now.

Serial port settings

Defaults were 9600 8 data bits, odd parity, 1 stop bit, TSIP input and output. The iQ_Monitor program allows you to change to other modes, but then you can no longer use it to talk to the SQ. This is bad. :-) I don't have a battery on my adapter board so I unplugged it for a few seconds and it went back to 'normal'.

TSIP is a proprietary Trimble binary protocol but it is well documented.

I checked http://www.freegis.org/ but could not find anything there.

Interfacing

Here is a paper I found about interfacing the SQ to another device.

http://www.eng.yale.edu/enalab/projects/MK2_GPS/MK2_LASSENGPS.pdf

Linux

Linux 2.6.12 finds the right driver and I can see it via minicom on /dev/ttyUSB0 but since the module comes up in TSIP mode (see above) it's not working yet under Linux. I plan on using this with a Bluetooth connection to my Dell X50V running Arcpad, so I am not sure if I care.