Earthmate USB to Serial cable

New_Compact · 02-04-2004, 04:44 AM

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 don´t 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 don´t use
the software supplied with the GPS (USA) because i live in Spain.

Sorry for my english!

Laidback · 02-05-2004, 05:37 AM

Quote: Originally Posted by New_Compact

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 don´t 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 don´t use
the software supplied with the GPS (USA) because i live in Spain.

Sorry for my english!

Well, AFAIK you can't convert USB data to serial without some sort of Chip/software to control it, so I'd say that you have a serial GPS mouse (otherwise why pins 5-9 etc?) that is converted to USB and by wiring to the pins you have you are by-passing the USB conversion! I may be wrong here!

But well done for finding that!

By the way, what area are you in? We're skiing next week at Sierra Nevada, woo hoo!

New_Compact · 02-05-2004, 06:57 AM

Quote: Originally Posted by Laidback

By the way, what area are you in? We're skiing next week at Sierra Nevada, woo hoo!

Hi,
I live close to Barcelona. Normally I go skiing to Cerler ( Huesca's Pyrenees ).
In this season I have 20 days of ski.

MatrixPC · 02-12-2004, 03:42 PM

Can you explain a little clearer I mean pin to pin connection?
Delor USB pin ------ Serial pin
1 --------------------??
2 --------------------??
3
4
5 GROUND

rgardjr · 02-13-2004, 05:02 PM

Quote: Originally Posted by MatrixPC

Can you explain a little clearer I mean pin to pin connection?
Delor USB pin ------ Serial pin
1 --------------------??
2 --------------------??
3
4
5 GROUND

I'll try and help. If you're asking about which USB pin goes to which Serial pin-it doesn't work like that. If you have a newer earthmate, you can see that the end of the cable that plugs into the GPS receiver has 12 pins. With a USB cable 5 of these pins are used. To use the GPS via serial 7 of these pins are used. The two cables use the same pins for power, gound and shield, but that's where it ends. The GPS data to and from the receiver is transferred using different pins because of the difference between the two standards. Can you make a serial cable by cutting up a serial cable and the Delorme USB cable-maybe. If the Delorme USB cable has wires going to all 12 pins than it's as easy as finding the wire that goes to pin 1 in the Delorme cable and connecting it to the wire that goes to pin 5 on the serial cable. You'd just follow the pinout that New_Compact provided:

Delorme Serial
Pin Pin
1----------5
9----------5
4----------1
5----------3
6----------2
7----------4
12--------Shield

I haven't cut open the USB Delorme cable, but I'm guessing that there might not be wires running to those pins used for the serial operation. I bought the serial cable from Delorme for $35 and it has worked perfectly to solve my hibernation problem that I had with the USB cable and USB to serial drivers. If you do cut open your Delorme USB cable, let us know if the wires are there for the serial pins.

kalito · 02-20-2004, 05:38 PM

has anyone try this as well? if so.. can you tell me if it works or not... thanx in advance.

rgardjr · 02-20-2004, 06:23 PM

Quote: Originally Posted by kalito

has anyone try this as well? if so.. can you tell me if it works or not... thanx in advance.

I'm pretty sure that New Compact has done this. Here's the original thread:
http://www.mp3car.com/vbulletin/gps/18929-earthmate-not-compatible-mappoint.html
My only concern would be that the USB cable that comes with the Earthmate doesn't have wires running to the serial pins on the plug which would complicate the needed splicing quite a bit.

kalito · 02-23-2004, 03:55 AM

can someone tell me if the image is correct or is it the opposite way

Laidback · 02-23-2004, 04:29 AM

Quote: Originally Posted by kalito

can someone tell me if the image is correct or is it the opposite way

http://www.hardwarebook.net/connector/bus/usb.html
http://www.hardwarebook.net/connector/bus/usb_tech.html

rando · 06-04-2004, 06:51 PM

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

Mellman · 06-10-2004, 04:51 PM

you know, its sad....bout 4 years ago i paid $45+shipping for a serial -> usb cable for my carputer.

MatrixPC · 06-15-2004, 11:31 AM

Rando, can you post the pic? I want to see what I can do to make mine as serial.
Thanks

rando · 06-23-2004, 02:17 AM

Sorry, the digicam is out of town with the lady. No matter, it's simple enough you don't really need a picture.

Just snap off the cover on the GPS end of the GPS<->USB cable that came with the Earthmate. You will see all 12 pins in there. Look at the existing wires and match them up to the pin numbering scheme below. The existing USB connections are in bold.

Delorme Earthmate II GPS - Pinout
----------------------------------
1 - GND
2 - USB Data+
3 - USB Data-
4 - +5V
5 - RS232 RXD
6 - RS232 TXD
7 - RS232 DTR
8 - +5v
9 - GND
10 -
11 -
12 - SHIELD

Here is the pin-out for a DB9 serial connector.

RS232 DB9 - Pinout
------------------------------------
1 DCD Data Carrier Detect — Input status Line
2 RxD Receive Data — Receives bytes into PC
3 TxD Transmit Data — Transmits bytes out of PC
4 DTR Data Terminal Ready — Output status line
5 SG Signal Ground
6 DSR Data Set Ready — Input status line
7 RTS Request To Send — Output status line
8 CTS Clear To Send — Input status line
9 RI Ring Indicator — Input status line

Solder the GPS TxD line (pin 6) to the DB9 RxD line (pin 2); the GPS RxD line (pin 5) to the DB9 TxD line (pin 3); the GPS pin 7 to the DB9 DTR line (pin 4); GPS GND (pin 1 or 9) to DB9 SG line (pin 5).

Next you need to supply a 5v source to GPS pins 4 or 8 (your choice). The simple thing to do here is just use the USB cable for power. To avoid confusion, you might want to lift the USB Data+/- pins in that case or make a USB power passthrough cable that only passes the +5V and GND signals but not Data+/-. Alternatively you could attach a standard PC molex connector.

That's it. As soon as the device gets power it will start to pump out an NMEA stream 4800/8/n/1. I believe the device will go into sleep mode if DTR goes low. By default, your PC will assert DTR high anytime the COM port is opened so (in general) you don't really need to worry about it.

If you still need pics, I should be able to take some next week.

asci01 · 07-13-2004, 10:28 PM

Quote: Originally Posted by rando

Sorry, the digicam is out of town with the lady. No matter, it's simple enough you don't really need a picture.

Just snap off the cover on the GPS end of the GPS<->USB cable that came with the Earthmate. You will see all 12 pins in there. Look at the existing wires and match them up to the pin numbering scheme below.

Delorme Earthmate II GPS - Pinout
----------------------------------
1 - GND
2 - USB Data+
3 - USB Data-
4 - +5V
5 - RS232 RXD
6 - RS232 TXD
7 - RS232 DTR
8 - +5v
9 - GND
10 -
11 -
12 - SHIELD

Here is the pin-out for a DB9 serial connector.

RS232 DB9 - Pinout
------------------------------------
1 DCD Data Carrier Detect — Input status Line
2 RxD Receive Data — Receives bytes into PC
3 TxD Transmit Data — Transmits bytes out of PC
4 DTR Data Terminal Ready — Output status line
5 SG Signal Ground
6 DSR Data Set Ready — Input status line
7 RTS Request To Send — Output status line
8 CTS Clear To Send — Input status line
9 RI Ring Indicator — Input status line

Solder the GPS TxD line (pin 6) to the DB9 RxD line (pin 2); the GPS RxD line (pin 5) to the DB9 TxD line (pin 3); the GPS pin 7 to the DB9 DTR line (pin 4); GPS GND (pin 1 or 9) to DB9 SG line (pin 5).

Next you need to supply a 5v source to GPS pins 4 or 8 (your choice). The simple thing to do here is just use the USB cable for power. To avoid confusion, you might want to lift the USB Data+/- pins in that case or make a USB power passthrough cable that only passes the +5V and GND signals but not Data+/-. Alternatively you could attach a standard PC molex connector.

That's it. As soon as the device gets power it will start to pump out an NMEA stream 4800/8/n/1. I believe the device will go into sleep mode if DTR goes low. By default, your PC will assert DTR high anytime the COM port is opened so (in general) you don't really need to worry about it.

If you still need pics, I should be able to take some next week.

Any luck with the pictures, please?

rando · 07-13-2004, 11:55 PM

Quote: Originally Posted by asci01

Any luck with the pictures, please?

Ha! I completely forgot. I'll try to put some up tonight.