ptk

I remember someone asking for GPS hardware with faster than 1Hz update rate.

I was recently doing my new CarPC and was playing with GPS modules from Sparkfun.

I am playing with the Venus GPS with SMA connector



Features:
* 51 channel acquisition and 14 channel tracking
* SkyTraq based chipset
* 10Hz max update rate (1Hz default)
* Integrated LNA
* Single 2.7-3.3V supply
* 3.3V TTL UART
* Power: 28mA tracking
* Sensitivity: -161dBm
* Accuracy: <2.5m
* Hot start: 1 Seconds
* Cold Start: 29 Seconds
* Supports active or passive antennas
* Supports SBAS (WAAS, EGNOS, MSAS)

The features in bold above stands out rather well. Having said that, this module talks in SPI or TTL, so you will need to interface to your system appropriately.

Also for those who wants to keep the GPS running, 28mA power requirement will be ideal.

__________________
***
CarPC Ver 4 completed. Aopen i45GMT-HD, C2D mobile 2GHz. Photofast 64GB SSD. Novatel EU-850D

MP3Car.com

 

DarquePervert

But does it output NMEA sentences for popular GPS navigation software packages?

__________________

Sicarius

From the datasheet at the link above:

ptk

but honestly, can't imagine any chipset not supporting NMEA

__________________
***
CarPC Ver 4 completed. Aopen i45GMT-HD, C2D mobile 2GHz. Photofast 64GB SSD. Novatel EU-850D

millsy

This might be of interest to those seeking higher than the standard 1 hz update rates,also is just plain interesting.

http://www.gpspassion.com/forumsen/t...TOPIC_ID=76813

ptk

finally got all my bits in.
the original board comes with card edge SMA. Brought in some RP-SMA edge bulkhead as all my RF connectors are RP-SMAs.



Desoldering the original card edge connector is very tricky as there are SMD components near by. I dremeled off the connector before de-soldered off the legs. Soldering on the new connector is fairly straight forward.



I use a Sparkfun Breakout Board for CP2102 mini USB to Serial to interface to the GPS board. This is a good choice in view of its compact size as well as availability of 3.3V power supply. I also ran a line from motherboard's on board disc battery holder to supply the GPS board to supply the SRAM (this will shorten your warm start time).



Both boards are shrinkwrapped after the wiring.








Tested the GPS with Skytraq's own GPSViewer software. It's clocking fantastic cold start time of between 21-30 sec while testing indoor. There is a fair bit of drift of between 2-4m while testing indoor. Will run further testing once i get the car pc back to the car.

__________________
***
CarPC Ver 4 completed. Aopen i45GMT-HD, C2D mobile 2GHz. Photofast 64GB SSD. Novatel EU-850D

Sicarius

Nice job of replacing the connector and all but I can't say I'm a big fan of hanging a board from soldered connections on a PCB especially in a vibration prone environment like a car. How come you didn't just get an SMA to RP-SMA pigtail so you could mount the GPS board on a more stable surface?

ptk

Sicarius. I did that with previous project. But this particular board is so small, i figure it's light enough to hang off the connector. further more, the board is so small, it's actually difficult to mount properly.

__________________
***
CarPC Ver 4 completed. Aopen i45GMT-HD, C2D mobile 2GHz. Photofast 64GB SSD. Novatel EU-850D

MP3Car.com

 

Sicarius

Well, as for mounting it, I figured some Velcro would handle that nicely.

Parakie

I'm looking to implement something similar for my build, as I was searching for a 5/10hz usb receiver that supports an external antenna. The CP2102 board is now out of stock, and apparently you can use BOB-00718 sku as the replacement. Is it just the rx, tx, 3.3v, and ground lines that need to be connected?

Has anyone else done this? How well does it work a few months in?

mrbean_phillip

Yes, that is the ones you'd need to connect - I'm using the BOB-00718 breakout board.

You may want to get a backup battery too - take care when connecting, there's one link to desolder first.

__________________
F6 Tornado Project Log - nearing completion

MP3Car.com