Can I get a 1 pps (pulse per second) pulse from the Parallax GPS ?
Bean
Posts: 8,129
Does anyone know if there is anywhere I can solder a wire onto the Parallax GPS to get a 1 PPS signal ?
Also I've heard that some GPS units the first serial start bit is aligned to the GPS 1 PPS, does anyone know if that is true on the Parallax GPS ?
Bean.
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Also I've heard that some GPS units the first serial start bit is aligned to the GPS 1 PPS, does anyone know if that is true on the Parallax GPS ?
Bean.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
The first rule to being successful is "Learn from your mistakes",
The second rule is "Be willing to make mistakes"
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
www.hittconsulting.com
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Comments
Based on a little (ok VERY LITTLE) research. SWAG --->It seems to be using the POLSTAR PM248 module (designed for CAR navigation systems, I figure.) The module does not seem to have a 1PPS signal leaving via the 6 pin cable and everything else is "under" the RF shield.
http://www.polstargps.com/html/download/Module/PMB-248.pdf Other than Power and Serial IO, everything else is under the hood.
BUT... It seems to be using the SONY CXD2951GA-4 chip under there. That Chip DOES have a 1PPS signal pin. See the specs. Finding it will be a chore.
Do you really want to unsolder the shield to do what you need? It would take some courage for me to do that.
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Post Edited (pwillard) : 9/1/2007 3:29:57 AM GMT
RAW mode:
there is a start bit every second on the serial I/O pin
SMART mode:
there is a start bit every second on a pad just below the surface mount IC as follows;
With the GPS unit antenna facing down and the ribbon cable closest to you, there are six pads just below the surface mount IC. The second pad from the left has a start bit every second.
Didn't find any clock signal anywhere exposed on the unit. Didn't want to put my scope probe on any of the pins of the IC. Not quit brave enough. The pins are to close.
Post Edited (LilDi) : 9/1/2007 5:59:25 PM GMT