SDS100/SDS200: How to make a GPS for the SDS-100 $42

[rbuxton]

Do you perhaps have site hold time set to something other than 0?

For reasons unknown, the Hold Time for some systems is 1 second.


What would 0 do for me?


side note: I just took a short road trip and the SDS100 seems to be starting/stopping systems correctly with the GPS hooked up.

 

[UPMan]

A very long hold time would delay GPS updates until the hold time expired. 1 second isn't going to affect that. 0 holds the minimum time necessary to typically catch all active channel grants/updates (typically 1-2 seconds).

 

[rbuxton]

A very long hold time would delay GPS updates until the hold time expired. 1 second isn't going to affect that. 0 holds the minimum time necessary to typically catch all active channel grants/updates (typically 1-2 seconds).

I'll change to 0 and see how that works out. Thanks!

 

[kas1263]

Could this be done with 436?

 

[Hit_Factor]

Could this be done with 436?

Yes, but instead of mini USB you'll need the correct 4 pin connector. I forgot what it's called. You'll find it if you search this forum.

Also, the power should go to just the GPS puck. Not to both the scanner and puck.

 

[NM1D]

Thanks for posting the 'how to' on this.

After building one myself, I have a few tips to offer to help others.

I found that the mini-USB connector shell does not have enough room to allow two cables to be retained, so reassembling the shell does not end up with a mechanically secure connection for the somewhat fragile mini-usb connectors. If any pressure is placed on the connector pins, they can slide out of the mini-USB connector, and you will end up with a bad connection.

Perhaps it was the cheap quality of the connectors that came from Amazon, but I came up with an alternate, method that ended up being much easier to build, and ended up being much more mechanically stable.

I suggest simply buying a mini-USB to USB cable. Look for one that has the combination of 28 AWG and 24 AWG printed on the cable. This means the power leads will be 24 AWG, which may be needed for proper operation. The cable should look almost exactly like the one that came with the SDS100, but probably without the ferrite close to the scanner mini-USB connector.

Don't bother ordering the mini-USB connectors from Amazon, but instead cut the USB cable above, then simply splice the GPS serial cable to the USB cable. Be sure to use heat shrink over the internal splice connections, as well as one over the outside of the splice. Connect the Red, Black and Green of the GPS cable directly to the same colored wire in the mini-USB cable (Red to Red, Black to Black, and Green to Green).

It works well, and is much easier to solder than that small mini-USB connector, plus you end up with something that will stand up to a little abuse over time.

I hope this helps someone.

 

[scfr]

I have a Trimble Placer GPS 450 RS232 unit. Can I connect the serial out straight to pin 2 or does it need converted from RS232 levels to USB levels?

Russell, I have the exact set up and the same questions as you. Did you have any luck? Also, how do you charge it and use the gps at the same time using the Trimble?

 

[nessnet]

The mini-usb connector is under an RF shield.
Somewhere in the past, [U]jonwienke[/U] posted a picture.
Basically, it's really hard to get to.
I wouldn't recommend this.

 

[mike_s104]

This link might help others make a cable.

http://forums.radioreference.com/threads/gps-cable-mod-for-uniden-scanners.307752/