Monday, May 6, 2013

GARMIN GLO and Bad-Elf PRO – Which one might be the best for your iPod or wifi iPad?

The comparison here is not aiming to provide very objective and precise analysis. It reflects my own experience in the field with both devices. I mainly use external modules when driving or during walks, if your usage scenario is different, your judgment on certain items can be totally different.

I use both external modules almost every day, as I need to test our iPhone/iPad speedometer app with them. Plus or minus points I’m giving are reflecting my subjective value for presence or lack of certain features.

The look. I tried to keep proportions right in those photos.  
Zero effort connection to iPad/iPod after initial bluetooth pairing +1. Yes +1. Yes
Visual indicators for GPS lock and battery status Only blinking leds with need to study the manual for what they mean. And it’s not the stuff I want to remember. +3. First-class backlit LED screen. Absolutely clear indication of battery level with 4 bars.
Status message saying if is it searching for satellites or number of satellites in the view.
Bad-Elf also gives you ability to see the speed, altitude and gps course without having any additional device.
GPS lock time +1. Around 30 seconds from cold state.
Few seconds in warm state (probably GLONASS + GPS make the difference here).
Around 30 seconds from cold state. A few seconds in warm state.
GPS Accuracy Claimed as up to 3 meters. Never witnessed by myself such an accuracy, it gives 5 meters for sure. Reliable 5 meters. 
An important note should be made here. GLO should be really achieving 3 meters and Bad-Elf its claimed 2.5 meters of accuracy. Problem here will be with how iPhone/iPad/iPod location services report this accuracy, as it goes now, you will not see values better than 5 meters.
Trustful GPS measurements -1 NO. Through many experiments with GLO vs just iPhone 5 GPS I should tell, the probablity of yourself walking on the roofs instead of the road is pretty high with GLO. I'd expect from GLO very reliable measurements. Unfortunately iPhone's GPS track often stayed on the road while GLO was jumping all the way to the roofs of buildings one would walk around. IT'S OK. It was closer to the real road on more occasions. Still, fantastically, iPhone 5 was doing better I should tell (probably GLONASS boost makes the difference).
Accelerometer NO. Having accelerometer would help saving battery as module would be able to switch to power-save mode when not moving. Done right, accelerometer can also improve precision of speed measurement.
Grip to a surface +2. 4 rubber pads for a great grip on a car dashboard Pretty hard to find a good place in a car closer to windshield where to put. Always slides to the sides.
Bad-Elf support provided input on this one, let me cite it here: "We decided not to provide a non-slip pad for the Bad Elf for a couple of reasons. First, there really is no need to place it in the windshield. Because the antenna is so good, we don't notice a degradation in accuracy if we keep it around our neck, in our shirt pocket, or in a cup holder. Second, if you do put it in the windshield, you have trouble reading the screen. So we hear from our customers that many of them just put velcro on it and place it somewhere that it's convenient for them, with no regard to the windshield."
Ability to override iPhone and cellular iPad built-in GPS Another tough one. I used to say that neither will override. Though I have an input from Bad-Elf now and let me just retest it. Here is response from Bad-Elf: "iOS *automatically* uses the location services stream that is reporting the best accuracy. That means that for both the Garmin and the Bad Elf, within a minute or so, all location-based apps will get the more accurate feed. No configuration or selection is needed. As for "boosting" the internal GPS performance, I don;t think that's what Garmin means. I think they mean that as soon as the external GPS is more accurate than the internal one, then you get the better feed for free. Same with the Bad Elf. To be fair, I think you should either remove this issue, or give Garmin and Bad Elf a tie on this issue.
I'm going to retest both modules with iPhone 4/5 connected and confirm this.
Ability to adjust GPS updates rate and report advanced data as number of satellites. NO. Only pushes as 5 updates per second. This is not bad to support up to 5 updates per sec, BUT having no option for slower updates is actually a BAD thing. It might kill some apps that are not ready for updates with such a rate. For speedometer app we had to make some implementation changes first time we confronted this update rate. There is no guarantee that all apps in AppStore will have this handled right. Default GPS update rate for iPhones and cellular iPads is 1 time per second and that’s what most of apps are designed for. YES OR NO.
If the APP that you use doesn't integrate Elf's SDK and is not reading location data directly via their SDK, then locations update rate will be about 1 per second, just as it is with the built in GPS module. No advanced location features will be available.
YES IF. If the APP in question does integrate Elf's SDK and reads data through it, then the APP can read data with up to 10 per second frequency and also report real GPS accuracy Elf module provides (up to 2.5 meters). 
You better ask the APP developers if they do integrate Elf's SDK and use advance capabilities of the external module.
Dedicated application in AppStore NO. +2 YES. This is absolutely must to have. You can configure many aspects of Bad-Elf module and what more having a GPS log transferred via it from module to iPad/iPod. After Bad-Elf module is connected you’ll be automatically presented with options to install the FREE app.
GPS logging NO. +1 YES. This feature might mean more positive points to someone else. But my scenario is a car based usage, so there will be some other app doing a GPS log. For someone out in the woods with iPad left at home, this is a GREAT option. Bad-Elf saves the GPS log, no need for any bluetooth connection so battery will last longer and later you can just transfer that log seamlessly to iPad and study there. COOL!
Reliable ON/OFF switch NO. I would not even expect putting this feature here and giving points for it. BUT, GLO's power on/off handling is totally lousy. Every time I wanted to use it, it was discharged. The power button is too soft and requires just a slight push to switch on – after that nothing stops the charged unit from eating the battery for no purpose. +2 YES. No chance you would switch Bad-Elf ON or OFF by mistake. A solid rubber power switch requires a stronger hold and uses some delay before reacting.
Support Typical big company support. They will “tell” you it boosts the iPhone 5 GPS but will never tell how and what exactly. Pretty fast response, but you'll hardly get the info you need. Premier support. I first approached Bad-Elf having a question from my customer. Not only they troubleshooted the issue very well and gave the solution, they didn't blame my app, me or the customer for holding their module wrong. It was fast and relevant response.
Availability Wordwide by GARMIN US goes without saying. I can see Bad-Elf now on and with just ok, close to US price, so I guess that ensures good availability and standard return/repair policy.
Price at the moment of writing 100 EUR, ~120USD 140 EUR, ~180USD.
You can probably get even lower "street" price in US, lucky you (I'm EU based :))!
Link to module page

Even with a reasonably higher price tag, Bad-Elf PRO is quite a winner for me. For the ultimate win, it would have to have GLONASS integrated and rubber pads to ensure it sits tight under my windshield.

I bought GARMIN GLO first and only after that I got to know about Bad-Elf PRO. Should I be more educated at that moment I’d go for Bad-Elf PRO only. May be I’d ask them when GLONASS+GPS model would be available :).

And then again, I can totally imagine GARMIN GLO as a perfect solution for a car being always plugged into charger. But to be perfect in this scenario it has to have adjustable update rate to cooperate nicely with 100% of location/navigation apps.

I’ll write more on both modules as time goes and I test them even more, though I thought putting my raw thoughts on paper now may help someone when picking the right module.

I don’t pretend to know everything, any chance GARMIN already has a configuration app for GLO? Any chance GLO has an accelerometer? Feel free to correct me in the comments and I’ll update the article for sure.

And as I’m taming myself to be a businessman :), here is a link to our iPhone/iPad speedometer and GPS tracker app that works totally fine with both of those external modules regardless GPS update rate:

iPhone/iPad Speedometer on AppStore
Yours, Stan.

P.S. You can also read on “GARMIN GLO plus iPhone – first impressions” where I’m trying to see if GARMIN GLO substitutes, improves or boosts your existing iPhone GPS in any way.

[Update May 7th, 2013: updated based on Bad-Elf's input, I don't expect any input from Garmin :), but I believe Bad-Elf was very helpful to explain external GPS specifics for both companies]

Also adding a link to Bad-Elf review I liked the most: (it goes through configuration app as well and comments are quite informative) and really great GARMIN GLO review here:

[Update March-2015] Bad-Elf added a new product that is superior to Bad Elf Pro, but also more expensive - Bad Efl Pro+. Here is the product page:

[Update 20-Apr-2015] There is an issue with External GPS modules and iOS8.3 release. Most of module manufactures issued statements saying they know about the problem and reported it to Apple. As of the moment, until Apple release the update, the only solution is to downgrade to iOS8.2:

[Update 4-Jul-2015]. iOS 8.4 fixes the issue with external GPS receivers. 


  1. Ouu. It really dissapointed me you saying Bad Elf has the same accuracy as Iphone 5, was thinking about buying the second edition of Elf, but now I probably look for something more accurate.

    1. Hi OrangeMoon, What happens (and there is no reason to not believe Elf's team on that) is that when Elf's external GPS is connected through the iPhone/iPad location module (if the APP is not talking to the external module via Elf's SDK), then location accuracy is reported by iPhone/iPad as 5 meters, even if Elf's module provides 2.5 meters precision samples. So even if the APP in question is not accessing Elf's data directly via Elf's SDK, accuracy of data should be still up to 2.5 meters, even if iPhone's location module would report 5 meters when seeing 2.5 on the input. This is based on my experience as an app developer and information from Elf provided some time ago.

  2. And one more question. If I use a third party App, will ot grab the Elf's GPS data inmediately? I mean from my App, when I save a POI. And thanx for the review

    1. Hi OrangeMoon. By default, after connection, Elf's external GPS receiver will be selected as a default source of GPS data by iOS location module (you might need to restart iPhone/iPad if this would not happen). Though the frequency of location samples will be about 1 per second in this default setup. For advanced features, like up to 10 location updates per second, the APP is question should use Elf's SDK directly. It's the best to ask the APP developers if they use Elf's SDK in their app. Yours, Stan.