Miscellaneous Projects

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= osmo-lea6t-gps =

The swiss makes of GPS receiver chips and modules u-blox has (among others), a line of so-called ''timing'' GPS modules.

The main difference of such modules compared to the standard modules is their ability to output arbitrary GPS-derived clock

signals anywhere between 0.25 Hz and 10 MHz.

This allows such modules to be used in a varity of high-precision timing applications where a simpler/traditional approach using

regular 1PPS outputs is not sufficient.

The Osmocom project has developed an evaluation / development board for the u-blox LEA-6T timing module.  Like all other

Osmocom projects, it is fully open source, i.e. schematics and layout files are freely available.

[[Image(osmo-lea6t_small.jpg)]]

== Electrical Design ==

=== Schematics and Layout ===

The most up-to-date versions of the schematics and layout files can be found in the projects git repository which can be

browsed at http://cgit.osmocom.org/cgit/osmo-lea6t-gps/ or cloned like this:

{{{

$ git clone git://git.osmocom.org/osmo-lea6t-gps

}}}

For your convenience, PDF files are also attached to the bottom of this wiki page.

=== Major components ===

 * LEA-6T Module ([http://www.u-blox.com/en/gps-modules/u-blox-6-timing-module/lea-6t.html product page], [http://www.u-blox.com/images/downloads/Product_Docs/LEA-6_DataSheet_%28GPS.G6-HW-09004%29.pdf data sheet])

 * FIXME: add more components here

== How to use ==

You can connect to it using one of the Osmocom-style serial cables (3.3V UART on 2.5mm audio jack) or using USB.  You will get

a serial port that can speak either NMEA or the proprietary UBX protocol.

The full protocol is specified in the [http://www.u-blox.com/images/downloads/Product_Docs/u-blox6_ReceiverDescriptionProtocolSpec_%28GPS.G6-SW-10018%29.pdf u-blox 6 protocol specifiation].

== Where to buy ==

You can have the PCB etched anywhere you'd like, using the layout data we have provided.  Most of the components

are available via distributors like Digikey.  Only the LEA-6T module has to be obtained through an u-blox distributor.

Alternatively, [http://sysmocom.de/ sysmocom] is selling DIY kits including the PCB and all components [http://shop.sysmocom.de/products/osmo-lea6t-gps in their webshop].  Please note that you still have to solder all parts by yourself.

== Who ==

osmo-lea6t-gps was designed by Sylvain Munaut.  Prototype manufacturing and testing was performed by Harald Welte of sysmocom.