summaryrefslogtreecommitdiff
path: root/GlobalPositioningSystem.mdwn
blob: e626032814861c9d278ef85dc598f9120d864728 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
## <a name="LV2 GPS CAN Node Information"></a> LV2 GPS CAN Node Information

### <a name="Current GPS Receiver:"></a> Current GPS Receiver:

- SiRF's (purchased Conexant which was originally Rockwell) Jupiter board
- Zodiac chipset (12 Satellite)
- Small. Good in high dynames. 5g's?
- Decent binary message protocol
- _Does_ have raw data output.

- Jupiter Board [[contacts|Minutiae/JupiterContactInfo]]
- Jupiter Board [[details (PDFs)|Minutiae/JupiterBoardInfo]].

### <a name="Jupiter Board Setup information:"></a> Jupiter Board Setup information:

Messages used:

> <table border=1 cellpadding=0 cellspacing=0>
>   <tr>
>     <th bgcolor="#99CCCC"><strong> # </strong></th>
>     <th bgcolor="#99CCCC"><strong> Name </strong></th>
>     <th bgcolor="#99CCCC"><strong> Data we get </strong></th>
>   </tr>
>   <tr>
>     <td> 1000 </td>
>     <td> Geodetic Position Status </td>
>     <td> Lock, UTC, Lat, Lon, Alt, expected error </td>
>   </tr>
>   <tr>
>     <td> 1003 </td>
>     <td> Visible Sattelites </td>
>     <td> Best possible xDOP&#39;s </td>
>   </tr>
>   <tr>
>     <td> 1009* </td>
>     <td> ECEF Position </td>
>     <td> ECEF X,Y,Z and Vx, Vy, Vz </td>
>   </tr>
>   <tr>
>     <td> 1102 </td>
>     <td> Measurement Time Mark Message </td>
>     <td> code and carrier phase data </td>
>   </tr>
> </table>
>
> <font>\* - Message # 1009 is called 1001 in v1.18 firmware and earlier</font>

### <a name="CAN Node Notebook:"></a> CAN Node Notebook:

<table border=1 cellpadding=0 cellspacing=0>
  <tr>
    <td> 05/20020 </td>
    <td> DY soldered up CAN node. Due to miscommunication, 2mm connector was on wrong side. Corrected. Added red LED on D0. Added 7805 in place of 78L05. </td>
  </tr>
  <tr>
    <td> 08/25/2002 </td>
    <td> Programmed both Jupiter boards (v1.18 and v2.30) using LABMON. Seems to have programmed into the EEPROM. </td>
  </tr>
  <tr>
    <td> 08/26/2002 </td>
    <td> The Jupiter board we have has a straight through OSX connector for the GPS antenna. This sucks since turns out the OSX cable connector sticks way out of the connector... it requires at least 0.625&quot; to take OSX plug out... less if you don&#39;t have to remove it. I used the FC&#39;s 0.625 stand offs as a temporary measure - seems to work. Can modify in the future. However, the longer inter-board distance meant that the 2mm connector to the Jupiter board no longer reached - I had to put 2mm pins on the CAN node and use a 20mm 1.5&quot; ribbon cable to connect it. </td>
  </tr>
  <tr>
    <td> 08/26/2002 </td>
    <td> Tried out board with PIC in reset. 260mA - which is about right, consider 220mA for the receiver, with 40mA left over for the PIC and active antenna. New problem: power drop in the 7805 = (12V - 5V)*(0.260A) = 1.82W! Duh! Next time, do the loss calculation BEFORE hand. The only quick fix solution I see is either running it off a seperate 6V (puke) or getting a small DC-DC converter to replace the 7805. </td>
  </tr>
  <tr>
    <td> 08/26/2002 </td>
    <td> Found a bunch of TI &quot;7805 replacement&quot; SPS&#39;s. TI part # <a href="http://focus.ti.com/docs/prod/productfolder.jhtml?genericPartNumber=78SR105" target="_top">78SR105</a> (PDF below), Digikey has them. They&#39;re huge (8 x 23 x 24 mm) but c&#39;est la vie. There were others, but they were either bigger (the PT series) or had worse ripple (78STxxx series). Mounting is going to be a real problem... i don&#39;t want to have to add another board, and there isn&#39;t any real screw mounting options... it looks like double sticky foam tape is going to save the day again! </td>
  </tr>
  <tr>
    <td> 08/27/2002 </td>
    <td> Got the 78SR105 today and it worked great. Takes in 12V at 140mA and puts out 5V at 260mA which is about 77% efficient (it&#39;s burning off roughly 380mW). Tim found a great way to mount it on the board so that two of the pins of the thing could be soldered directly on the board. I chose to use clear silicone to mount it to the board since sticky tape couldn&#39;t be found, and it should be a lot stronger since there&#39;s not much surface area for the sticky tape. After about 5 minutes of running, the SPS got slightly warm, but not as warm as the GPS main processor! Eventually, after the PIC&#39;s mod wires are siliconed down, we really out to zip tie the SPS down for safety. </td>
  </tr>
</table>

### <a name="Safety thoughts on the GPS:"></a> Safety thoughts on the GPS:

1. ALWAYS have an ACTIVE antenna connected when the Jupiter board is on.
2. Make SURE the PIC's port pins are configured properly.

----

### <a name="Other links and information:"></a> Other links and information:

#### <a name="GPS Antennas:"></a> GPS Antennas:

- <http://www.gpssource.com/htdocs/l1ant.html>
- <http://www.navtechgps.com/supply/covert.asp> - $35 (26dB active)
- <http://www.navtechgps.com/supply/mmouse.asp> - $80 (29dB active)
- <http://www.navtechgps.com/supply/arincant.asp> - $200 (13db)
- <http://www.micropulse.com/26800.htm>

#### <a name="GPS Antenna Combiners:"></a> GPS Antenna Combiners:

- <http://www.gpsnetworking.com/products/cpdc2x1.htm>
  - <http://www.fedcenter.com/fedsites/GpsNetworking/hot15.htm> - $295
- <http://www.gpssource.com/htdocs/c2x1.html>
- Homebrew splitter! <http://home-2.worldonline.nl/~samsvl/splitter.htm>

#### <a name="Other:"></a> Other:

- <http://www.qsl.net/n9zia/wireless/appendixF.html#6> - 2.4GHz Splitter/combiner

#### <a name="GPS Antenna Pre-amplifiers"></a> GPS Antenna Pre-amplifiers

- Homebrew pre-amped GPS Antena: <http://www.scott-inc.com/html/gpsant.htm>
- Above recommends the following kick ass amp (available for ~$2 via Avnet: [http://www.macom.com/products/products\_spec.jsp?pn=AM50-0002](http://www.macom.com/products/products_spec.jsp?pn=AM50-0002)

#### <a name="Notes on future GPS boards:"></a> Notes on future GPS boards:

- <http://www.navtechgps.com/supply/g12.asp> - 20g's! 20Hz! Possible to order board wo/restrictions. $2500. Oh well.
- [[SiGEM]] looked like it was for vehicles only.

#### <a name="Other Links:"></a> Other Links:

- <http://www.navtechgps.com> - Great [links](http://www.navtechgps.com/links.asp)

----
Attachments:

- [[78sr105.pdf]]
- [[GPS_UC_v3.brd]]
- [[GPS_UC_v3.sch]]