Small DIY GPS powered by BCD-436HP -- make it yourself!

[fourthhorseman]

One of the reason's that I believe Uniden stated was the possibility of interference at some freqs, birdies, something , also price, even if it only cost YOU 5 bucks, that might translate to 20 bucks or more price increase.

I think they have an internal GPS in that new CD/scanner thing. I'd also guess we will see it in the next generation of scanners now.

I wonder how that would work with a low in car mount though? I have my GPS antenna on the dash. Wonder if that chip/antenna has good enough reception? I do know earlier ones would loose it in weak signal areas and that newer chips do much better. (Been geocaching/mapping/etc/ since SA was turned off).

Ive seen No Interference...
I monitor across all services/bands.
LadyBird keeps the signal like a champ.
First cold fix was on my workbench, in my
house..with stock ceramic antenna. about 3
minutes..

and yeah, 5 bucks parts,,All of us would have been happy to
pay 20 for the feature to be there,,seems they could have put
a lotta smiles on faces..VS so much time spent on WIFI..That was a Cluster Funk!
Id rather have the GPS than WiFi..Which is more use able across the map..

But Oh..then they may have suffered a loss due to not as many sales
of that 80$ Uniden puck..that has like 9 diff cables..

This set up works for the 996XT, and the 536..(done 3 996XT's and 1 536)
and 3 436hp's
I use the UBLOX Neo6 for the base units..and the ladybirds for the handhelds.
Base units are fitted with a SMA for an external GPS antenna..either U.FL to SMA
or SMA to SMA depends on the UBLOX model..

SARENTEL antennas are great, and Very Low profile..(for base units)
https://www.amazon.com/gp/offer-lis...ms?ie=UTF8&selectedSims=B00CRCGUBW,B00K9ZZY7K

Currently getting ready to open up a 396XT and go to work..there IS enough
room in there! getting a BCT15X in this week..Should be easy too..


Have no fear, Trust your ability , and Void yer Warranty!..
But GPS with no wires..
TOTALLY worth it!

 

[fourthhorseman]

Man. That's even easier than getting to the pins on the connector!

Path of least resistance brother..First try was removing the USB/GPS input shield..that took Forever..then
found the TX/RX pads..that were Right in front of my face...Tunnel vision..had to step back..use the
multitester to verify the tracks..then it was full steam ahead..

 

[ShyFlyer]

It's not that Uniden couldn't do this, it's that they made a conscious decision to not do it.

I think they have an internal GPS in that new CD/scanner thing. I'd also guess we will see it in the next generation of scanners now.

I think that the "guts" of the GPS are internal, but I know for sure it uses an external antenna.

 

[fourthhorseman]

It's not that Uniden couldn't do this, it's that they made a conscious decision to not do it..

HoooRayyye..The first apologist has surfaced..LoLz..

 

[ShyFlyer]

Apologist? Hardly. But if it makes you feel better, then go ahead and think that. Keep in mind I didn't say that Uniden made the right choice.

 

[fourthhorseman]

Apologist? Hardly. But if it makes you feel better, then go ahead and think that. Keep in mind I didn't say that Uniden made the right choice.

No need to feel better..I always feel fine, but thanks for the warm thoughts.

In a thread like this, that you have contributed zero to, why even mention it unless your trying to stir the pot..

Bring some meat to the table instead of pinchin of others plates...

 

[fourthhorseman]

I'm going to take this project one step further and embed an HC-05 Bluetooth module with a TTL/RS-232 converter in the radio (either an HP-2 or a BCD436) and have it paired to a likewise HC-05 mounted in the trunk and permanently.powered. That way I can grab and go with my 436 or HP-2 and it will automatically pair up and provide GPS support in the car without having to connect any other cables other than antenna and power to the scanner.

Ive been milling this over, Im concerned primarily about any leakage from the BT module..GPS is RX only, but the BT will TX also..wondering how that will play out..
Please post your findings..Pics are optional at this point, but all would appreciate..
the parts fit easily and the connections are obvious..

 

[K5MPH]

Where would the interference come from would it be some type of harmonic from the GPS antenna itself or the power being supply to it from the scanner itself,not saying there will be any interference just making a observation from a previous post,i know its RX only i was thinking maybe from the board itself......

 

[K5MPH]

Ive seen No Interference...
I monitor across all services/bands.
LadyBird keeps the signal like a champ.
First cold fix was on my workbench, in my
house..with stock ceramic antenna. about 3
minutes..

and yeah, 5 bucks parts,,All of us would have been happy to
pay 20 for the feature to be there,,seems they could have put
a lotta smiles on faces..VS so much time spent on WIFI..That was a Cluster Funk!
Id rather have the GPS than WiFi..Which is more use able across the map..

But Oh..then they may have suffered a loss due to not as many sales
of that 80$ Uniden puck..that has like 9 diff cables..

This set up works for the 996XT, and the 536..(done 3 996XT's and 1 536)
and 3 436hp's
I use the UBLOX Neo6 for the base units..and the ladybirds for the handhelds.
Base units are fitted with a SMA for an external GPS antenna..either U.FL to SMA
or SMA to SMA depends on the UBLOX model..

SARENTEL antennas are great, and Very Low profile..(for base units)
https://www.amazon.com/gp/offer-lis...ms?ie=UTF8&selectedSims=B00CRCGUBW,B00K9ZZY7K

Currently getting ready to open up a 396XT and go to work..there IS enough
room in there! getting a BCT15X in this week..Should be easy too..


Have no fear, Trust your ability , and Void yer Warranty!..
But GPS with no wires..
TOTALLY worth it!

Can you post your info here when you do your BCT15x,i have the BCT15......

 

[ShyFlyer]

No need to feel better..I always feel fine, but thanks for the warm thoughts.

In a thread like this, that you have contributed zero to, why even mention it unless your trying to stir the pot..

Bring some meat to the table instead of pinchin of others plates...

I'll post when and where I want.

Until I have verified information that Uniden lacks the ability to integrate a feature (such as GPS), then the logical thing to do is assume that Uniden willfully chose not to do it. Criticize them for that.

 

[fourthhorseman]

I'll post when and where I want.

Until I have verified information that Uniden lacks the ability to integrate a feature (such as GPS), then the logical thing to do is assume that Uniden willfully chose not to do it. Criticize them for that.

Verified...LOLz..the verification,,My436's have internal GPS..Yours dont..Ha..If ya even gots one....
You seem like a dog with no bone..

Woof.

 

[fourthhorseman]

Can you post your info here when you do your BCT15x,i have the BCT15......

No problem, The base units are easier to work, the trace's on the PCB are less crammed than the handhelds..
I have a 396tx and a 15x on the bench, Ill photo both and post up.
I may try to a youtube the job, vid would be better than words...


This thread should be getting a WIKI soon, we need to all post up pics and parts lists, me included..

 

[wx5uif]

My parts are on the way!


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[ShyFlyer]

Verified...LOLz..the verification,,My436's have internal GPS..Yours dont..Ha..If ya even gots one....
You seem like a dog with no bone..

Woof.

Wrong again. Just because you and other users have built a functional integrated GPS for your scanners does not in any way shape or form prove that Uniden is incapable of doing the same. The only thing you and the other users have proven is that it is possible.

Quite often companies, especially tech oriented companies, hold back new features so that they'll have something "new" and "revolutionary" to introduce with the next generation product. It sucks, but it's a common practice. Could Uniden be doing this? Probably, probably not. However, I think it's better to assume this than complain/accuse Uniden of being incompetent.

 

[jonwienke]

I just modded my 436 to add an internal GPS. I used this module: https://www.amazon.com/Gowoops-Ceramic-Passive-Antenna-Raspberry/dp/B01AW5QYES

The thickness of the patch antenna (25x25x4mm) required that I make a 1-inch square cutout in the rear of the case to make room for the GPS module. But other than that, installation was pretty straightforward. I chose the module because the larger antenna had better bandwidth and sensitivity specs than some of the smaller ones, the module has a battery backup for faster fixes once the module has gotten a lock, and it was only $20.99.

Preliminary tests seem to indicate everything is working OK, I will be taking it on a road trip tomorrow to see how well it works.

 

[jonwienke]

The module is rated 3.3-5V so I didn't bother with a voltage regulator, just wired it and the RS232 chip to the 3.7V pad. The only change I had to make in the scanner config was to change the serial rate to 9600.

 

[jonwienke]

Everything worked perfectly. The scanner had no trouble keeping its location updated, even in the back seat of an SUV with the patch antenna facing downward (the scanner sitting on the seat in a cradle leaning back at an angle).

 

[wx5uif]

I done the same mod this weekend to mine. I used a Ladybird 3. I originally had it hooked to the 3.7v pad, but found it isn't switched when the power is off. I did open it back up tonight and found the VCC pad is 3.33v and is switched. Locks on to signal fairly quickly.


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[Markb]

So just to confirm, these are the 2 pins for GPS data?

Also, is there any programming that needs to be done the GPS module? I just ordered a Ladybird 3 an am wondering if I need a cable to program.

Lastly, is the addition of a switch to shut off the GPS necessary or worth adding if I use the VCC pad for power?

Thanks to all for the info. I am looking forward to doing this as soon as the parts show up.

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[jonwienke]

I originally had it hooked to the 3.7v pad, but found it isn't switched when the power is off.

That is incorrect, the 3.7V pad IS switched. It's where I have my GPS module connected, which draws 20-50mA, depending on whether it has satellite lock or not. With power off, my scanner only draws .02mA, which is about 1/1000 of the current drawn by the GPS when it is powered on.

If you got voltage on the 3.7V pad while power was off, it was probably residual charge from a capacitor.