Rechargeable External GPS Project

[DennisKink]

Cool.

 

[jonwienke]

The shipment of cases has hit customs, so I should have them by Wednesday or so.

 

[jonwienke]

The new cases are in, and the design is updated as follows:

1. The GPS has a DB-9 female connector.

2. The GPS can be used with the Homepatrol I or II, 396, 436, or SDS100 with the Uniden BWZG1844001 DB9 male to 4-pin female adapter cable. (https://www.amazon.com/Uniden-BWZG1844001-BCD436HP-BCD396XT-Homepatrol/dp/B007JYZL5O/).

3. It can be used with mobile scanners with a DB9 straight-through cable.

4. The new case is slightly smaller than the original one, so the maximum number of batteries that will fit is 2. This will still give 48 hours or more of total use on a single charge. I also switched from 14500 cells to rechargeable CR123s. They have very similar capacities, approximately 800mAH per battery. This will be the standard battery configuration going forward.

5. The batteries are replaceable without soldering, just unscrew the 4 screws holding the top in place, pull the batteries out of the holder, and insert new ones. Be very careful to observe polarity, or you will have magic smoke emission problems.

6. I've decided that trying to make the thing waterproof is not really feasible. Neither the micro-USB nor the DB-9 connectors are designed to be exposed to the elements for extended periods of time. For typical vehicle use, having the GPS outside the vehicle is unnecessary anyway.

7. The unit still powers on automatically when connected to a scanner that is powered on. Turning off the scanner, or disconnecting the unit from the scanner turns it off.

8. I am now offering a mod to allow USB-powered scanners to charge and power the GPS when plugged into USB power. If the GPS is plugged into USB power, it will feed USB power to a modded scanner. If USB power is removed, then the scanner and GPS will continue to operate on their batteries, but the scanner will not run off the GPS battery or vice versa.

Price for the base GPS unit is $60. If you already have the Uniden 4-pin GPS adapter cable, you don't need any additional cable to use the GPS with any scanner with the 4-pin GPS port. I offer a 9-foot adapter cable for $10 if you don't already have one. If you want to use the GPS with a mobile scanner, I recommend getting a DB9 straight-through cable from any computer/electronic supply source.

Updated photos here:
https://1drv.ms/f/s!ApJIS-l4xqPtgvBlzW0NYoY4W7MvJw

 

[buddrousa]

John you have my email and other info build me a 9pin 2 battery unit and let me know when to send payment

 

[jonwienke]

Paypal me the $60 and I will send it out Monday.

 

[jonwienke]

One note: The $60 is for the GPS. I charge whatever the actual shipping cost happens to be on top of that. In most cases shipping will be $7.20. International, AK, and HI will probably be higher.

 

[buddrousa]

Jon check you account

 

[jonwienke]

Got it, thank you.

 

[JamesO]

Just wanted to give some purchase/user feedback on this Rechargeable External GPS unit.

Luckily either Jon had some of these units built and in stock or was able to quickly assemble and ship as I ordered one and it arrived very quickly.

Unit is compact for what is has in it and is simple and easy to use. Just remember to set the GPS serial link data rate to 9600.

Not a problem with the GPS, but my HomePatrol-1 had a flaky/damaged GPS connector when i purchased it, the connector in the scanner really needs to be replaced. So on my HomePatrol-1 it was a but tricky to get the auto power on to detect and stay engaged. I needed to have some pressure on the cable as it connected to the scanner so the GPS would stay on. Again, not a problem with Jon's device, but beware if you have a worn/damaged mini serial jack on your scanner, it can give you some problems.

First day, I used the GPS, I had it running about 12 hours with no problem. Quick to acquire satellites and I just left the unit on the console in my truck in the cup holder, worked fine.

Small and easy enough to travel with the unit, even if you are not driving. Take the GPS so you do not need to try and deal with Zipcode programming, I have been to some places where finding the Zipcode is not so easy!

Cost is very reasonable when comparing to other options and a single cable no power required make for a simple portable set up. With a rental vehicle you never know how many cigarette lighter sockets will be available, if any, so you may be required to take a cigarette lighter Y adapter, just one more thing to drag around with you!

Simple transaction, simple operation, quick delivery. What else could someone ask for other than the GPS to be integrated into the radio and to have the 2 letter state abbreviation as part of the Site or System names.

 

[jonwienke]

One note: The $60 is for the GPS. I charge whatever the actual shipping cost happens to be on top of that. In most cases shipping will be $7.20. International, AK, and HI will probably be higher.

I just shipped a GPS to Canada, and it was about $26 just for shipping.

 

[jonwienke]

Simple transaction, simple operation, quick delivery.

Thank you.

Regarding the connector issue, there isn't much I can do about that. The GPS unit has to get the power-on signal from the scanner to know to power on, and if the connector doesn't pass that signal, the GPS can't know to turn on.

 

[buddrousa]

Jon thanks for the good work and fast shipping the new 9 pin worked great all day yesterday the long 436 version is also still working great.

 

[jonwienke]

Thank you.

 

[JamesO]

Thank you.

Regarding the connector issue, there isn't much I can do about that. The GPS unit has to get the power-on signal from the scanner to know to power on, and if the connector doesn't pass that signal, the GPS can't know to turn on.

Again, not a problem with the GPS, just a problem with some scanners with the Mini Serial connectors that may have had a hard life, so if you are considering the portable GPS make sure your Mini Serial connector is in good shape or prepare to replace it as needed.

 

[jonwienke]

It can also be the cable if the metal spring tab on the back of the plug doesn't have enough tension. You can fix that by sliding an x-acto knife blade or small flat jeweler's screwdriver under the tab to bend it up a bit. Just don't go crazy or you can break the tab.

 

[JamesO]

In my case the cable end is not the problem, the cable is almost brand new. The problem is clearly the socket in the scanner. When there are chunks of the plastic connector body missing from the connector, I think the problem is pretty obvious.

I did not have a problem with the same cable and the Uniden GPS puck as it worked fine, but the battery powered GPS much require a different signal or signal level to trigger and turn on With the crappy female socket, I had to route the cable with a bit of tension in one direction to keep the GPS on. I just wanted to make sure anyone that plans on using the battery powered GPS module with a portable scanner be aware that if their socket has seen better days, they may need to replace the socket.

This again is not a fault of the battery powered GPS module, it just required a different signal that the Uniden GPS did not require and for what ever reason it is more sensitive to the need for a Mini Serial connector that needs to be in good shape.

I have a few of the connectors somewhere around here, had to move stuff around about 20 times since I bought them, so it may be time just to order some more and replace connector. Just one more thing on the TODO list.

 

[jonwienke]

The Uniden puck doesn't have a power-on signal. It turns on whenever it gets 5V from the lighter plug adapter. The battery unit can't work that way, or it would never shut off. Instead, it looks for a -5V signal (RS232 logic 0) coming from the scanner, which connects the battery to the GPS via a p-channel FET. So if the RS232 data out pin from the scanner is damaged (the source of the -5V power-on signal), the Uniden puck will work, but mine won't.

If there are pieces missing from the connector, I agree that it is time to change it.

 

[garys]

This is totally off topic, well at least a bit off topic. Other than the software, what would the challenges be to putting WiFi into the 436? It would be nice to be able to use Siren with the 436 as well as the 536. Especially when traveling.

 

[mule1075]

This is totally off topic, well at least a bit off topic. Other than the software, what would the challenges be to putting WiFi into the 436? It would be nice to be able to use Siren with the 436 as well as the 536. Especially when traveling.

I am guessing RFI that's why the 536hp uses a dongle. Just a guess though I could very well be wrong.

 

[JamesO]

The Uniden puck doesn't have a power-on signal. It turns on whenever it gets 5V from the lighter plug adapter. The battery unit can't work that way, or it would never shut off. Instead, it looks for a -5V signal (RS232 logic 0) coming from the scanner, which connects the battery to the GPS via a p-channel FET. So if the RS232 data out pin from the scanner is damaged (the source of the -5V power-on signal), the Uniden puck will work, but mine won't.

If there are pieces missing from the connector, I agree that it is time to change it.

This makes sense that the data "Output" is the problem, because with the Uniden GPS puck it is just sending data to the "Input" pin and I had no problems with the GPS puck.

Just for clarity and so people understand the shape the jack is in, I have attached a picture. Notice that the entire side plastic part of the outer bezel over the metal support is missing along with about 1/2 of the inner terminal spacers and support. How this happened and what caused this is anyone guess, I assume the GPS plug got jacked/stressed pretty badly at one point, this is how I received the unit and until now it has not been a problem, but it has been on the back burner to repair. Looks like it has moved up a few notches in the priority since needing a solid connection for the external GPS.