SHOW CASE OLD

SHOW CASE

To demonstrate how easy and cheap it is to build your own GPS IRDA Converter, this page will show you how a complete set was build step by step. This will include a list of costs made.

In this example a complete set is build which is going to use a Haicom HI-203E serial GPS mouse. This GPS mouse by default sends NMEA 0183 messages @4800 baud.

HaiCOM HI-203E

STEP 1. Get the PARTS

PARTS LIST

Prices of parts are list prices of CONRAD electronics in the Netherlands.

Part	Value	Part number	Price
C1 Capacitor	10nF		0,24
C2 Capacitor	100nF		0,24
C3 Capacitor	100nF		0,24
C4 Capacitor	330pF		0,19
C5 Capacitor	330pF or 1nF		0,19
D1 IR Diode	SFH482 or equivalent	144698-44	0,46
D2 Diode	1N4148	162280-44	0,05
IC2	NE556		0,73
R1	10K Ohm		0,11
R2	8K2 Ohm		0,11
R3	8K2 Ohm		0,11
R4	100K Ohm		0,11
R5	390 Ohm		0,11
R7	5K6 Ohm		0,11
CASE	70x60x30		2,54
9P SUB-D Male			0,54
9P SUB-D Female			0,54
14p IC FITT.			0,14
MINI DIN 6P PS/2			1,87
3.5mm STEREO JACK CONN.			0,78
POWER CONN. 2.1 mm			0,82
7805 Voltage regulator			0,54
LABOUR	5 HOURS	YOU	?,??

Total			11,77

STEP 2.

This part is probably going to take some time. I was able to build the complete PCB in about two hours. See the result build on a small piece of experiment board.

STEP 3.

Because the future owner of this GPS IRDA Converter was also interested in attaching a laptop computer to the converter, the following connectors have been build in the case:

1. RS232 9pins Sub-D connector Male (GPS in)
2. RS232 9pins Sub-D connector Female (PC out)
3. Power supply connector (2.1 mm) (12 volts in)
4. Jacket 3.5mm (IRDA out)
5. PS/2 style 6 pins connector female (GPS power supply 8 volts)

These connectors were build into a small plastic case (LxWxH; 70mmx60mmx30mm)
It took me about 1,5 hour to drill to right holes in the plastic case. I used a small drill device (Dremel) to accomplish this. The print was then screwed into the case and the connectors were wired to the print.

STEP 3.

I use a oscilloscope to test the unit. If you do not have one, you could test the unit by attaching the GPS in connector to a pc and use HyperTerminal to send information. On the PDA I use a terminal emulator (Dejavu or PockeTTY) to check the in-coming characters.
When using a scoop, you should wire the input line to GND to check the existence of 20uS pulses at the output pin 9 of the NE556. If these pulse do not exist, check pin 5 of the NE556 for a (little more than) 4800Hz pulse signal. If build the print correctly, you should not have any problems.

When testing the unit on the PDA, you should check that in Pocket PC 2002 the Beam Setting is unchecked in Setting->Connections->Beam. Otherwise you will not be able to check the checkbox in the TomTom GPS utility.

In the TomTom GPS utility for the protocol use NMEA 0183v2 4800. For the port setting use Native IR: and check the checkbox to activate these settings.

DO NOT use COM3 or any other COM setting as this will block your PDA and a hard reset is necessary to be able to use the PDA. In the worst case you will not be able to undo this setting and you will need to re-install the GPS software.

GPS Receiver, Converter and PDA