Earthmate USB to Serial cable
Hi,
I have received several e-mails asking about the serial cable.
This is my experience with this cable:
Ask the technical service of Delorme for to construct myself the cable and this was the answer.
De: Brian Riendeau
Fecha: 10/14/03 20:45:17
Para: 'jose*****@******.com'
Asunto: RE: Email Support Site Form
Hi,
The GPS does not output anything that is compatible with a standard
serial connection regardless of how you wire it. It outputs a binary data
stream per USB specification. The USB to Serial adapter cable actually has
a microchip built into it that converts the binary data to an output that
can then be routed down a serial cable for use with PDAs and other devices
that require a NMEA 0183 compliant signal and have no USB port.
Thanks,
Brian
After this answer I went to Delorme's page and buy the serial cable but
I had an error and they sent the cable to me for a PDA ( palm m500 ).
I live in Spain and for me the shipping charges are more expensive than the cable.
Then i open the cable and surprised I donīt saw any microchip. Look up the pins
Of the connector of the PDA and translate them to a connector of the serial port.
The cable is working perfectly with 5 meters length.
And this is the wiring of the cable:
Cable USB GPS Delorme Earthmate
Conector GPS Conector USB
1 ----------------------- 4 - USB - GND
2 ----------------------- 3 - USB - DATA +
3 ----------------------- 2 - USB - DATA -
4 ----------------------- 1 - USB - + 5 VDC
12 malla ---------------- masa conector (shield)
Cable Serial GPS Delorme Earthmate
Conector GPS Conector D9 Hembra (D9 female)
1 - 9 ------------------- 5 - GND
4 ----------------------- 1 - + 5 VDC interior PC cable rojo *
5 ----------------------- 3 - <- TXD
6 ----------------------- 2 - -> RXD
7 ----------------------- 4 - <- DTR
12 malla ---------------- masa conector (shield)
* Power supply from inside of PC (hacked). When you switch on the PC you
have main power and the GPS start to seeking satellites.
- Use the USB cable for reference for the pins of the GPS.
- For me is working perfectly whith any GPS software. I donīt use
the software supplied with the GPS (USA) because i live in Spain. :)
Sorry for my english! :(
How to make a serial cable for the USB Earthmate
I just did this (from information posted elsewhere) and it works. It's true, the GPS to USB cable DOES NOT have all the wires you need to get a serial connection. But, if you look close at the GPS end of the GPS/USB cable, you will see that the connector is easily disassembled with a couple of clips. Once inside, all 12 pins are exposed and more than long enough to solder the extra wires you need. I will post pics of this when I get home.
Here is what I did to test it out. I plugged in the USB cable to the GPS and to the computer so that i would get power and ground. There were no drivers installed on this machine ... I'm only doing this to get power and ground. Next I loaded up hyperterminal and pointed it to com1/4800/8/n/1. Finally I plugged in a serial cable to com1 and shorted pin 2 (READ) to pin 6 on the GPS. I immediate began receiving the GPS data stream below.
$Version 231.000.000ES-01501
$TOW: 0
$WK: 1192
$POS: 6378137 0 0
$CLK: 104538
$CHNL:12
$Baud rate: 4800 System clock: 24.553MHz
$HW Type: S2AM
$Asic Version: 0x23
$Clock Source: GPSCLK
$Internal Beacon: None
$LED Flash rate : OnTime: 0 , OffTime: 0
$GPGGA,235948.000,0000.0000,N,00000.0000,E,0,00,50 .0,0.0,M,0.0,M,0.0,0000*77
$GPGSA,A,1,,,,,,,,,,,,,50.0,50.0,50.0*05
$GPRMC,235948.000,V,0000.0000,N,00000.0000,E,0.00, 0.00,091102,,*1E