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Anyone here have experience with Bad Elf GPS products?


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Looks nice. The biggest issue I see is that they don't publish their sensitivity values. If you can find those, you are good. They should be in the high -150dBm range, into the -160dBm is exceptional.

 

I used to use one of these

http://www.gpscentral.ca/products/usglobalsat/bt-821.html

That was when I had an early smartphone without a great GPS.

Edited by Andronicus
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Does iOS not have bluetooth? Not being an apple guy, sometimes apple's complete lack of intercompatability shocks me.

 

Yes, of course.... But IOS has a somewhat custom Bluetooth language and the way in which position data is reported to an IOS device is different than a standard BT device. This requires specific programming and a specific app for the IOS device. If buying a BT GPS, you just need to make sure it states it is IOS compatible.

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Yes, of course.... But IOS has a somewhat custom Bluetooth language and the way in which position data is reported to an IOS device is different than a standard BT device. This requires specific programming and a specific app for the IOS device. If buying a BT GPS, you just need to make sure it states it is IOS compatible.

I'll file that way in the brain bank for future reference. You're saying that iOS doesn't understand standard NMEA sentences?
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...You're saying that iOS doesn't understand standard NMEA sentences?

I don't think he said that, and I think you're putting it in the wrong context.

 

iOS does not "understand standard NMEA sentences." Neither does Android, or Windows, or Linux for that matter.

 

iOS includes a set of routines called CoreLocation. These accept input from multiple sources (built-in GPS, cellular and WiFi triangulation, data streams from compatible Bluetooth or wired/connected devices) and uses all of that to make location data available to any application that calls for it. The application doesn't have to know how to read the data streams or even where the data came from; it just requests the location from the operating system.

 

A gross simplification perhaps, but no worse than asking if it understands NMEA sentences :D

Edited by user13371
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Looks nice. The biggest issue I see is that they don't publish their sensitivity values. If you can find those, you are good. They should be in the high -150dBm range, into the -160dBm is exceptional.

 

I used to use one of these

http://www.gpscentral.ca/products/usglobalsat/bt-821.html

That was when I had an early smartphone without a great GPS.

 

You're right they don't. I wonder how we can get the sensitivity value? Is there an industry standard in determining the sensitivity values or it's subjective?

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Looks nice. The biggest issue I see is that they don't publish their sensitivity values. If you can find those, you are good. They should be in the high -150dBm range, into the -160dBm is exceptional.

 

I used to use one of these

http://www.gpscentral.ca/products/usglobalsat/bt-821.html

That was when I had an early smartphone without a great GPS.

 

You're right they don't. I wonder how we can get the sensitivity value? Is there an industry standard in determining the sensitivity values or it's subjective?

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...You're saying that iOS doesn't understand standard NMEA sentences?

I don't think he said that, and I think you're putting it in the wrong context.

 

iOS does not "understand standard NMEA sentences." Neither does Android, or Windows, or Linux for that matter.

 

iOS includes a set of routines called CoreLocation. These accept input from multiple sources (built-in GPS, cellular and WiFi triangulation, data streams from compatible Bluetooth or wired/connected devices) and uses all of that to make location data available to any application that calls for it. The application doesn't have to know how to read the data streams or even where the data came from; it just requests the location from the operating system.

 

A gross simplification perhaps, but no worse than asking if it understands NMEA sentences :D

OK. Let me try it another way entirely. He said "But IOS has a somewhat custom Bluetooth language". How am I to interpret this? That they have their own stacks that ignore the standard BT profiles for something out in left field? I don't think that's the case. iOS shouldn't be directly interpreting BT SPP data anyway - one needs an intermediate app of some sort. Data across SPP can be literally anything.

 

Still looking for some understanding of what was actually meant by his statement.

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EC: Does this help? iOS Supported Bluetooth Protocols

 

SPP isn't supported. A fair follow-up question might be what BT protocol do iOS-supported GPS gadgets use? I dunno. Ask BadElf. Or Dual. Or Garmin. or DeLorme - they all make Bluetooth GpSRs that work with iOS, while the more common GlobalSat and myriad inexpensive imported ones don't.

Edited by user13371
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I had no more questions, Red90. It's down to a fairly simple equation. Apple isn't supporting the Bluetooth SPP profile, and that's the profile that the Elf device cited above requires.

 

As far as I can see, Apple does not "have a somewhat custom Bluetooth language", they just don't support the requisite Bluetooth profile for these devices. For a fair length of time (up to about 2.3, where it sorta worked), Android didn't, either.

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All of the Bad Elf products work with all IOS devices (listed below). They are specifically designed for that one purpose and nothing else.

 

Compatibility:

 

iPod touch (2nd, 3rd, 4th & 5th generations)

iPhone 5S, 5C, 5, 4S, iPhone 4, iPhone 3GS, & iPhone 3G

iPad Air, iPad (3rd & 4th generations), iPad 2, iPad

iPad mini with Retina display, iPad mini

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...All of the Bad Elf products work with all IOS devices ... They are specifically designed for that one purpose and nothing else

Well, not precisely. Primarily intended for iOS, but the Model listed at the start of this thread has USB connection and can use that to stream NMEA sentences to Macs and PCs. Maybe that feature is the source of confusion here.

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And the answer is...

Lee,

 

Happy to help and feel free to copy the below to the forum ... looks like there is a good deal of contention on this subject.

 

Our Bluetooth devices (PRO, PRO+, GNSS) are designed for use specifically with Apple Devices. This means a couple of things have happened ... but let's start with the full bluetooth spec. for Apple here: https://developer.apple.com/hardwaredrivers/BluetoothDesignGuidelines.pdf

 

- As an MFI company we are registered with Apple and they detect this with subsection 2.1.1. (...Device ID profile lets the Apple product identify the implementation of the remote accessory...)

- We are also using the iAP(iPod Accessory Protocol), Section 7

- There is also the integration of an Authentication Chip from Apple.

 

The support of non-iOS devices by our devices was a later development - Bluetooth is bluetooth after all so why not. The elf handshakes with the device on the other end of the pair - if it's an Apple device, it just works as above. If it is a non-iOS device the PRO begins to stream NMEA sentences using SPP. At this point it would be up to the individual operating system what happens.

 

As was part of the discussion on the Forum with Android you would need to use a Mock Location Emulator to parse out the NMEA into something useable. We recommend Bluetooth GPS (https://play.google.com/store/apps/details?id=googoo.android.btgps&hl=en)

 

With any other operating system (OSx, Windows, Linux, etc.) it is up to the individual application to handle the decoding.

 

Best Regards,

 

John McLellan

C.H.ElF (Chief Helper Elf)

Bad Elf, LLC

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Looks nice. The biggest issue I see is that they don't publish their sensitivity values. If you can find those, you are good. They should be in the high -150dBm range, into the -160dBm is exceptional.

 

I used to use one of these

http://www.gpscentral.ca/products/usglobalsat/bt-821.html

That was when I had an early smartphone without a great GPS.

 

You're right they don't. I wonder how we can get the sensitivity value? Is there an industry standard in determining the sensitivity values or it's subjective?

I don't think you can 'get' the sensitivity value. This is a value that is determined by the RF designers. Some manufacturers will publish these numbers (especialy if they are proud of them), and others won't (expecialy if they are ashamed of them).

 

My rule of thumb is "If the sensitivity is not published, JUST SAY NO!" There is nothing more dissapointing than trying to use your new GPS, but it can't get a lock because of tree cover.

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As I said, you'd have to ask the makers of the iOS-compatible GPSRs what protocol they use - but it isn't SPP.

Just to finish my iOS hate rant...

While the industry had standardized on NEMA via serial protocol, and have been using it for years very successfully, apple in all their wisdom decides that they have a better idea. And, instead of adding their better idea, they remove the old method; thus making all the great cheap products available incompatible, and likely requiring developers of iOS compatible devices to pay a license fee.

 

While it may be a good business strategy as long as you have an army of iDiots mindlessly buying your product, this, and other similar "featurs", are the reasons I will never buy an iOS device.

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It is a LOT more complicated than sensitivity. It is "simple" to detect all of the radio signals. The hard part is figuring out what is a bounced signal and what is a direct signal and applying the complex math to determine true position. When "high sensitivity" receivers came out, it really was not that they had designed better radio. In the past the receivers would ignore weak signal as it was assumed these were reflected. The big change was when the designed work out the algorithms that allowed the processing of the reflected signals. Back when they first cam out, you could see a big difference between brands as some had better math than others. To me, what ends up being more important is how good the algorithms are that are used and not some sensitivity value.

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Just did a quick google.

 

I currently have a QStarz Bluetooth GPS. I don't really use it much anymore (it is a pain in the butt to use with Android).

 

Anyway, if you jail break your iOS device, it looks like you can use normal Bluetooth GPS, including QStarz, and GlobalSat models. I think the jail break process enables Bluetooth SPP (serial port profile), allowing normal Bluetooth GPS to work.

 

From my understanding, iOS intentionally does not support many of the standard profiles in the Bluetooth stack. So Red90 said "somewhat custom Bluetooth language", would probably have been more accurate to say "somewhat crippled Bluetooth Stack", or "somewhat incomplete Bluetooth Stack".

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It is a LOT more complicated than sensitivity. It is "simple" to detect all of the radio signals. The hard part is figuring out what is a bounced signal and what is a direct signal and applying the complex math to determine true position. When "high sensitivity" receivers came out, it really was not that they had designed better radio. In the past the receivers would ignore weak signal as it was assumed these were reflected. The big change was when the designed work out the algorithms that allowed the processing of the reflected signals. Back when they first cam out, you could see a big difference between brands as some had better math than others. To me, what ends up being more important is how good the algorithms are that are used and not some sensitivity value.

Well, I am not a GPS designer (although, out my office window, is Novatel GPS, maybe I could ask them) so I don't have the answers to this. But, I would think that by now, there is likely an open source algorithm that is considered "as good as it gets." I suspect that the math side is not nearly as big of an issue as it once was.

 

I guess the true test would be to do some comparisons downtown. Are there any brass caps downtown anymore (or did they all get archived)? Maybe we could host an event and let everyone try their GPSr out for accuracy and stability in the middle of all the tall building.

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No, the algorithms are built into the GPS chips themselves. What is better to know is what specific chip the device is using. the GPS "unit" manufacturers do not make the chips on which the math is performed.....

 

http://www.brighthub.com/electronics/gps/articles/65460.aspx

 

"Sensitivity" numbers in dbm are really meaningless. If the chip can't make a useful location from the multipath signals, it won't give you the correct location. If you want to test this...walk up to a tall building that is by itself and turn on your GPS. Due to the high reflected signal nature, the chance of it determining your position at a mirrored location inside the building are high.

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I currently have a QStarz Bluetooth GPS. I don't really use it much anymore (it is a pain in the butt to use with Android).

A little earlier you complained Apple doesn't let you use generic bluetooth GPSRs - yet here you're saying the cheap generic GPS is a pain to use with Android.

 

Bluetooth GPSRs made for iOS - not just Bad-Elf, but other mainstream mnanufacturers like DeLorme, Garmin, and others - work seamlessly with every location-aware service on the iPhone or iPad, without jailbreaking.

 

The original discussion point in this thread is Bad-El - the folks there were kind enough to answer questions. Can we continue in that direction?

Edited by user13371
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I currently have a QStarz Bluetooth GPS. I don't really use it much anymore (it is a pain in the butt to use with Android).

A little earlier you complained Apple doesn't let you use generic bluetooth GPSRs - yet here you're saying the cheap generic GPS is a pain to use with Android.

It may be a bit of a PITA, but it does work (unlike iOS)

Bluetooth GPSRs made for iOS - not just Bad-Elf, but other mainstream mnanufacturers like DeLorme, Garmin, and others - work seamlessly with every location-aware service on the iPhone or iPad, without jailbreaking.

You just made my point. Now manufacturers have to make normal bluetooth GPS and special non standard iOS bluetooth GPS. Increases their cost of buisness, and that is passed on to you, the iOS owning customer. No thanks, I won't participate in that sillyness.

The original discussion point in this thread is Bad-El - the folks there were kind enough to answer questions. Can we continue in that direction?

I think I have already answered that question. i.e. If they don't have thier sensitivity numbers published, don't buy it.

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I currently have a QStarz Bluetooth GPS. I don't really use it much anymore (it is a pain in the butt to use with Android).

A little earlier you complained Apple doesn't let you use generic bluetooth GPSRs - yet here you're saying the cheap generic GPS is a pain to use with Android.

It may be a bit of a PITA, but it does work (unlike iOS)

Bluetooth GPSRs made for iOS - not just Bad-Elf, but other mainstream mnanufacturers like DeLorme, Garmin, and others - work seamlessly with every location-aware service on the iPhone or iPad, without jailbreaking.

You just made my point. Now manufacturers have to make normal bluetooth GPS and special non standard iOS bluetooth GPS. Increases their cost of buisness, and that is passed on to you, the iOS owning customer. No thanks, I won't participate in that sillyness.

The original discussion point in this thread is Bad-El - the folks there were kind enough to answer questions. Can we continue in that direction?

I think I have already answered that question. i.e. If they don't have thier sensitivity numbers published, don't buy it.

 

I have to admit I'm not very impressed with Bad Elf's customer service. I emailed them a few days ago asking for sensitivity information. I got no response from them. Not sure if they care about potential customers like me.

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If they don't have thier sensitivity numbers published, don't buy it.

That's something I have never, ever considered in purchasing a GPS. There are other metrics I look at, product reviews, and real world use cases. There's one spec on the Bad-Elf that puts me off though - unrelated to GPS itself -- waterproofness, or lack thereof. IPX4 for field use? Sorry, no.

 

I emailed them a few days ago asking for sensitivity information. I got no response from them. Not sure if they care about potential customers like me.

Perhaps they looked at your other threads here and saw exactly what kind of customer you would be :D

 

But seriously. I emailed the question about their Bluetooth profile one evening after dinner and the reply (which I re-posted at their encouragement) was in my inbox the next morning. I wonder what accounts for the difference?

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We'll see. I just sent an inquiry to their support address.

 

But y'know, I think I can guess at the answer. In one of the Q&A sections of their website, they mention the Pro+ uses the MediaTek MTK3339 - which you could guess from their other advertised specs(66 channel, 10hz update rate, GPS+Glonass). And devices from other vendors almost always quote MediaTek's own -165dB figure.

 

Whether or not that means anything in the real world, once it's in a complete package, is something else altogether. Maybe it's one of those "all else being equal" (though they never are) kind of things.

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And again, BadElf replies. Even apologized for a delay in reply - though asked on Friday afternoon and answered Monday morning is fine by me.

 

Lee,

 

Sorry for the delay in getting back to you -

 

Yes the PRO+ employs the MTK3339 as the GPS engine ...

Acquisition: -148dBm, cold start

Reacquisition: -163dBm, Hot start

Tracking: -165dBm

 

...

 

Best Regards,

 

John McLellan

C.H.ElF (Chief Helper Elf)

Bad Elf, LLC

 

So I guessed right on -165dBm tracking, and there are your acquisition cold and hot start numbers.

Edited by user13371
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