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

[Hit_Factor]

Making a GPS for the SDS-100, total cost is about $42.

I searched for and read lot's of threads. This is what worked for me. Hopefully it will save you some time or money.

Buy a GlobalSat BR-335-S4 $30-$35 on Amazon http://a.co/3aMYTZk

Buy a pack of mini usb male type b plugs $7 on Amazon http://a.co/bLeFpvi

Find an older USB cable in your junk drawer. It needs a female type A end on it (the end that plugs into a computer or charger), the other end doesn't matter because you are going to cut it off. Look for the largest gauge wire. If the wire is too small it may not carry enough current for the scanner.

Cut the end off of the GPS puck and USB cable. Don't forget to slide some heat shrink tube over the wires before you start soldering.

Solder the red wires together and to pin 5, Black wires together and to pin 1, Green wires together and to pin 2. I soldered wires to the three pins on the USB plug first and then soldered the 3 different sets of wires to the leads. Solder the bare wires together. The white wires are not used. Sketch it out before you start soldering - I should have done that to save time and rework.

This cable will power the GPS and the scanner. The attached picture shows the pinouts and wires.

When you plug your new GPS/cable into the scanner and a power source the scanner should show GPS at the bottom of the screen. To test the operation of the GPS, use the zip services button and enter the zip code for a distant city. Watch the scanner, it should change to your local area automatically.

 

[kevino]

Wrong link for connectors?

Link provided for connectors is for micro USB connectors, not mini USB connectors.

 

[N9PBD]

I think this is a better link for Mini USB connectors: http://a.co/jh69who

 

[Hit_Factor]

Link provided for connectors is for micro USB connectors, not mini USB connectors.

Thanks - good catch, thanks, micro connectors is what you need http://a.co/4CpTi2c

 

[tumegpc]

Thanks for sharing. This mod should also work with the 325P2.

 

[Russell]

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?

 

[jonwienke]

The scanner requires RS232, even though it's being fed in through a USB connector.

 

[Hit_Factor]

I would try the connection of serial out to pin 2. I tried a lot of different things and stopped as soon as 1 worked. None of those things hurt the radio.

It looks like your GPS has a separate power cable so the other connections dont need to be considered.

 

[nessnet]

Hit_Factor:
Wouldn't he need a ground also?
(In addition to pin 2).

 

[Hit_Factor]

Hit_Factor:
Wouldn't he need a ground also?
(In addition to pin 2).

Nope, the white wire, data -, I'm told, is for programming the gps. Changing baud, etc. Don't need that capability.

The black is the ground for the 5vdc.

 

[bagmouse7]

Thanks Hit_Factor!

This solution is working perfectly, I used the GlobalSat BR-355-S4 and the USB connectors that N9PBD posted, The USB ends worked perfectly and I was able to clip the end on properly for a super clean look.
The GPS puck has a red led that you can see to verify the status. It seems to sync up almost immediately, even indoors.
You can go to the WX scan page on the SDS100 to see the GPS Longitude/Latitude on the display.

The wires are tiny and it is a pain the get the wires stripped properly, but it works great once it's all put together.

 

[jonwienke]

Hit_Factor:
Wouldn't he need a ground also?
(In addition to pin 2).

The GPS ground and scanner ground need to be tied together, both for the GPS signal and USB power.

 

[Hit_Factor]

You guys are correct. He should tie in the grounds, even with the separate power supply. I wasn't catching the context of the question.

 

[jonwienke]

The grounds have to be connected, otherwise the GPS won't power on, or the scanner won't charge when you plug the cable into USB power. Or both.

 

[pinballwiz86]

I still don't understand why Uniden won't add a GPS chip to their scanners. (At least the mobile/base version! Instead of giving us wi-fi..which is cool and all but still)

Yes, it consumes more power--add a larger battery pack.

 

[jonwienke]

The GPS mod I do only decreases battery life by about 4% on the SDS100. It's not even worth installing a power switch to optionally turn it off.

 

[hagensieker]

Just ordered that puck and mini usb connectors.

One question. Why solder the green wire from the USB cable onto Pin 2. It isn't carrying data. The green one to the GPS puck would be though.

Or was it just done to tie down the green wire for neatness?

Brilliant idea. Can't wait to try it.

 

[nessnet]

If you put all wires to their proper connector, you now have a setup that will do GPS, power the scanner AND pass data to a computer, for Proscan (remote control, logging and recording/streaming).

Just be aware that if you also use Proscan for recording/streaming, (by connecting your PC line in via the headphone jack), there may be a lot of data noise from the radio. A ground loop filter worked to get rid of it:

https://www.amazon.com/gp/product/B001EAQTRI/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

 

[hagensieker]

If you put all wires to their proper connector, you now have a setup that will do GPS, power the scanner AND pass data to a computer, for Proscan (remote control, logging and recording/streaming).

Just be aware that if you also use Proscan for recording/streaming, (by connecting your PC line in via the headphone jack), there may be a lot of data noise from the radio. A ground loop filter worked to get rid of it:

https://www.amazon.com/gp/product/B001EAQTRI/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

Gotcha. I was thinking one way data transfer. Wasn't thinking about the other way and software on the computer. Thanks.

 

[AllenSchultz]

My SDS100 arrives tomorrow. I was wondering, could the GPS puck be attached to the back of the scanner and the wire leads soldered to the pins on the connector inside the scanner? This would require penetrating the case, but that would avoid having a connector plugged in all the time. Keep in mind, I am asking this question without seeing the scanner or the GPS puck. I really like the idea of having an aftermarket GPS installed but I would rather do it myself so that it can be undone if warranty service is required. My soldering skills are exceptional and I have a microscope for such work. Any thoughts?

Thanks,

Allen