Problems with Haicom HI-204III

[SyncMaster]

Hi,
I wanna use mapthis and so I want to connect my HI-204 to my PSP. According to the how2 by deniska I built with the psp remote a connection cable from the PS2 plug of the gps device to my psp. TX of GPS is connected to RX of PSP, GND to GND. Now, my GPS device needs external voltage, where should this go in? There is a pin for RX and one for VCC left. With my multimeter I tested the car adapter of the gps and it showed my that current is on tx and another pin that has no function mentioned in the manual. What to do? Please help me.

[SyncMaster]

Now I tried to connect it, the GPS reveives, I can see a light in it. But if I connect it to my PSP, GPS TX to RX of PSP and GND to GND (current is GND and VCC) mapthis doesn't do anything, I start GPS and it shows no satellites.

[deniska]

Now I tried to connect it, the GPS reveives, I can see a light in it. But if I connect it to my PSP, GPS TX to RX of PSP and GND to GND (current is GND and VCC) mapthis doesn't do anything, I start GPS and it shows no satellites.

First, make sure you get some kind of communication going - use lia serial echo program to see if you get anything on the screen....

[SyncMaster]

I followed deniskas instructions and made a screenshot of GPSlim236 with my GPS.
[IMG][/IMG]

[SyncMaster]

So, how can I use mapthis now?

[deniska]

It looks like it's not reading the data correctly (skipping some bits... so the greenscreen program and MapThs would not parse it since they check the parity...
Are you using a resistor in your connection? if not - you may want to incert a small resistance value in to a circuit.. (who knows, maybe the '0' level is too high for PSP's seral port...

If you are using the resistor - try using smaller value...

You are pretty close - so try tweaking your connection a bit....
You should get a standard NMEA sentences... examples could be found on the web or in gps.txt file bundled with MapThis 0.3

[SyncMaster]

Did I understand you correctly?
I should try different resistors until I find one where the PSP only shows letters from A-Z, numbers from 0-9 and "*"?
No notes, "$" etc?

I used serveral resistors. How high should the voltage be that goes into the psp?

[deniska]

The voltage should be around 2.5V..
You should get back something close to following:
$GPRMC,013426.000,A,4041.3130,N,07400.0635,W,17.78 ,200.06,041206,,,A*41
$GPVTG,200.06,T,,M,17.78,N,32.9,K,A*08

$GPGGA,013427.000,4041.3084,N,07400.0658,W,1,08,1. 3,9.2,M,-34.2,M,,0000*62
$GPRMC,013427.000,A,4041.3084,N,07400.0658,W,17.38 ,200.06,041206,,,A*41
$GPVTG,200.06,T,,M,17.38,N,32.2,K,A*07

$GPGGA,013428.000,4041.3040,N,07400.0679,W,1,08,1. 3,9.4,M,-34.2,M,,0000*60
$GPRMC,013428.000,A,4041.3040,N,07400.0679,W,16.06 ,200.02,041206,,,A*4D
$GPVTG,200.02,T,,M,16.06,N,29.7,K,A*00

$GPGGA,013429.000,4041.3002,N,07400.0699,W,1,08,1. 3,9.5,M,-34.2,M,,0000*68
$GPRMC,013429.000,A,4041.3002,N,07400.0699,W,13.96 ,200.36,041206,,,A*4F
$GPVTG,200.36,T,,M,13.96,N,25.9,K,A*09

$GPGGA,013430.000,4041.2969,N,07400.0716,W,1,08,1. 3,9.6,M,-34.2,M,,0000*60
$GPGSA,A,3,06,02,10,26,21,24,07,29,,,,,2.5,1.3,2.1 *3C
$GPGSV,3,1,11,29,63,158,43,10,56,044,43,26,50,177, 35,06,49,270,39*79

[SyncMaster]

Oh oh,
I cannot find a solution. I tried a variable resistor, but I could not get a good signal. Always some dots free, smileys etc. . Btw, there is no voltage of 2,5 V. The voltage I on GND and RX of the PSP changes the whole time.

[deniska]

Sorry that you can't figure it out. This is always a chance with new devices..
By voltage I ment the amplitude of the signal...
It would be hard to mesure, unless you have special equipment... because of the frequency of that signal..
The PSP expects 2.5V signal input.. my guess is that your device produces less than that...so that PSP cannot read it correctly...

If you still want to use your device, you may consider building a level converter...
some schematics, parts and tutorials are available on ps2dev.org's PSP hardware forums...