Project

General

Profile

Osmo-lea6t-gps » History » Version 7

laforge, 02/21/2016 10:37 AM

1 6 laforge
{{>toc}}
2 1 laforge
3 6 laforge
h1. osmo-lea6t-gps
4 1 laforge
5 6 laforge
6
The swiss makes of GPS receiver chips and modules u-blox has (among others), a line of so-called _timing_ GPS modules.
7
8 2 laforge
The main difference of such modules compared to the standard modules is their ability to output arbitrary GPS-derived clock
9
signals anywhere between 0.25 Hz and 10 MHz.
10
11
This allows such modules to be used in a varity of high-precision timing applications where a simpler/traditional approach using
12
regular 1PPS outputs is not sufficient.
13
14 1 laforge
The Osmocom project has developed an evaluation / development board for the u-blox LEA-6T timing module.  Like all other
15 2 laforge
Osmocom projects, it is fully open source, i.e. schematics and layout files are freely available.
16 1 laforge
17 7 laforge
!osmo-lea6t_small.jpg!
18 1 laforge
19 6 laforge
h2. Electrical Design
20 1 laforge
21 6 laforge
22
23
h3. Schematics and Layout
24
25
26 1 laforge
The most up-to-date versions of the schematics and layout files can be found in the projects git repository which can be
27
browsed at http://cgit.osmocom.org/cgit/osmo-lea6t-gps/ or cloned like this:
28 6 laforge
<pre>
29 1 laforge
$ git clone git://git.osmocom.org/osmo-lea6t-gps
30 6 laforge
</pre>
31 1 laforge
32
For your convenience, PDF files are also attached to the bottom of this wiki page.
33 4 laforge
34 2 laforge
35 6 laforge
h3. Major components
36 2 laforge
37 6 laforge
* LEA-6T Module ("product page":http://www.u-blox.com/en/gps-modules/u-blox-6-timing-module/lea-6t.html, "data sheet":http://www.u-blox.com/images/downloads/Product_Docs/LEA-6_DataSheet_%28GPS.G6-HW-09004%29.pdf)
38
* FIXME: add more components here
39
40
41
h2. How to use
42
43
44 1 laforge
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
45
a serial port that can speak either NMEA or the proprietary UBX protocol.
46
47 6 laforge
The full protocol is specified in the "u-blox 6 protocol specifiation":http://www.u-blox.com/images/downloads/Product_Docs/u-blox6_ReceiverDescriptionProtocolSpec_%28GPS.G6-SW-10018%29.pdf.
48 2 laforge
49
50
51 6 laforge
h2. Where to buy
52
53
54 2 laforge
You can have the PCB etched anywhere you'd like, using the layout data we have provided.  Most of the components
55
are available via distributors like Digikey.  Only the LEA-6T module has to be obtained through an u-blox distributor.
56
57 6 laforge
Alternatively, "sysmocom":http://sysmocom.de/ is selling fully assembled boards "in their webshop":http://shop.sysmocom.de/products/osmo-lea6t-gps.
58 2 laforge
59 6 laforge
60
h2. Who
61
62 4 laforge
63
osmo-lea6t-gps was designed by Sylvain Munaut.  Prototype manufacturing and testing was performed by Harald Welte of sysmocom. 
Add picture from clipboard (Maximum size: 48.8 MB)