Building instructions GPS support kit

A large picture of the assembled PCB can be seen here (2200*1800, 400kB).

Building the GPS kit is not very difficult, if you have some soldering experience with this kind of projects. If you do not have any soldering / building experience, and don't know the difference between the hot and cold side of a soldering iron, i suggest you buy the kit build and tested, or buy a ready-to-use product.

A large A4 drawing of the component layout (2 times enlarged) can be downloaded here and printed.

Handle the GPS module with the usual respect for static electricity. Do not remove the module from it's antistatic bag before you really need it, and make sure your work place is not sensitive to static charge buildups.

Start with a check of the component list. These are the components Make sure you can identify every piece. For a large picture of this overview click here. The supercap (upper right in this picture) is not included, but as option available.

List of materials

Part list GPSbase4 PCB
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count description    assembly order reference:
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1     GP2304 PCB enkelzijdig
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6     Draadjumper    4E pitch    A J1,2,3,4,5,6
1     56E weerst.    4E pitch    A R2
2     4K7 weerst.    4E pitch    A R3,R4
1     100E weerst.   4E pitch    A R5
1     470E weerst.   4E pitch    A R6
1     10E weerst.    4E pitch    A R7
1     3K9 weerst.    4E pitch    A R8
1     5K6 weerst.    4E pitch     A R10 (R9 is not used)
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4     1uF 50V elco   1E pitch.    B C9,10,11,12   mount flat on PCB!
8     100nF cond.    2E pitch     C C1,2,4,5,8,13,14,15
3     47uF 50V elco 1E pitch     E C3,C7,C16
1     220uF 50V elco 2E pitch     E C6
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1     MAX232CPE      DIL 16       G U1
1     LT1107 CN8-5   DIL 8        G U2
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2     3,3uH spoel    5E pitch     B L1,L3
1     47 uH spoel    5E pitch     B L2
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1     1N4004 Diode      4E pitch A D2
1     BYV10-40 Schottky 4E pitch  A D3
3     1N4148 sil. diode           A D5,D6,D7
1     P6KE 27A Tranzorb 5E pitch  B D1
1     LED 3mm                     C D8
1     SMAJ 5.0A Tranzorb SMD      G D4 on solderside below C6
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4     3-pin male conn.            D SW1,2,3,5
1     2-pin male conn.            D SW4
5     Shunt voor SW1-5            F SH1,2,3,4,5
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1     T315mA Zekering             F F1
1     Zekeringhouder              C FH1
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1     20 pin 2mm Female PCB conn. B Con2
1     DB9 Conn. Fem. Haaks PCB    F Con1 mounting optional
1     RJ-45 Connector voor PCB    F Con3
4     Printsteun LMSP-5-01 Richco F
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Optional extra's:
1     GoldCap 0,22F for GPS module C2
1     Antenna, active [or passive]

1     Strapu 2006 case
4     Parker 2,2 x 6,5 mm for mounting PCB
4     Ring 2,2 mm for mounting PCB

1     Antennacable with OSX/MCX connector
1     Ni-Cd or Ni-MH Accu 3V6 120mAH(max) Bat1

Building tips

Tools: a bending tool, good soldering iron for fine electronics, wirecutter, pincet.

Some generic tips for building:

Building the PCB can best be done by starting with the lowest (smallest) components, marked "A" in the component list. Put the resistors (inluding the 0-ohm resistors) and small diodes on the PCB. Mount the resistors and coils all with the color coding left-to-right or top-to-bottom. Do not bend the wires after putting the components in the PCB, instead put a piece of soft plastic foam over the devices, turn the PCB around and make sure the foam keeps on pressing against the components you just put in, and presses them gently against the PCB. Solder the components, cut the wires and repeat this procedure for the somewhat larger components marked "B", etcetera. The electrolytic capacitors and and connectors are mounted after everything else is done..
The 4 elco's near the MAX232 must be mounted flat on the PCB, as can be seen on the photograph.
There is a row of 12 jumper pins in the kit. Cut it in 4 3-pin jumpers with a wirecutter. Push the jumper over the pins *after* soldering the pins into the PCB.
The 315mA fuse is mounted in a socket! The socket is oldered in the PCB, the fuse goes into the socket...
R9 is an open location on the PCB. It is used when the adjustable version of the LT1107 is used in the circuit. The fixed 5V version is delivered with the components, so R9 is not used.
Do not use an ic socket for the MAX232 chip (not included anyway). The module will not fit anymore. You can use an ic socket for the LT1107 if you want.
The LED has a long and a short wire. The long wire is the anode and goes into the hole on the right side, the short wire is the kathode.
Optionally you can mount the LED a bit higher on its wires and drill a 3,5mm hole in the case above the LED. The wires on the LED are long enough. Dont let the LED come outside the case, or the PCB will be damaged if you put something on top of the case.
Mounting the 9 pin D connector is optional. All signals are also available on the RJ45 connector. Think about the wiring you need to make before you mount the DB-9.
The PCB mounts on which the GPS module is tightened must undergo a small operation before use, because it is extremely difficult to remove the module when it is not done. Cut away the center hook with a small wirecutter, as can be seen below.
One of the components must be mounted on the solder side. The part - the 5V SMD Transzorb - must be mounted under and parallel to the C6 electrolytic capacitor. The marking on the Transzorb must be connected to the positive wire of the C6 cap.

When all components are placed, check again the correct placement of the electrolytic capacitors, the diodes and IC's. Use the component layout that you can see and download above.

Also check the solder joints carefully. Especially at the 20p connector, where the solder joints are very tightly spaced.

Brush the solder side of the PCB with a short-haired brush. Small solder drops will be removed and it is easyer to see mistakes or bad solder joints.

When this is all done we can start testing the PCB.

Mounting supercap on GPS module.

By mounting a supercap on the GPS module, or by soldering a 3,6V NiCd cell on the support PCB the recovery time or "time to fix" will be much shorter.

The PCB goes into the box

The Strapu 2006 case for which the GPS support PCB was made must undergo some work

One of the case PCB mounting supports must be removed. The plastic GPS module PCB mounting support is on the same place and extends below the support PCB.

It can be cut away with a small wirecutter. Put it halfway the PCB support tab and cut it away in 2 times. Dot cut it away in one try, you could damage the case because of the high forces needed.

The GPS Support PCB is tightened with 4 small parker screw 2.2*6.3 mm with a ring.

The hole for the antenne connection that is shown above, is for the situation where you connect an antenna directly through the case onto the module. If you want to make an adapter cable to for example a BNC connector in the case, the hole should be made on another place in the Strapu case. There is enough place somewhat higher on the above picture, especially when the NiCD space on the PCB is not used.

The rectangular hole on the right is for the RJ45 connector. The RJ45 is somewhat higher as the bottom part of the case, so from the cover also some material has to be removed.

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