Bad Elf GPS Pro Issues

Discussion related to external and internal GPS / GLONASS / Galileo / BeiDou sensors
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widarecu
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Bad Elf GPS Pro Issues

Post by widarecu »

Hi,


Checking previous posts and the iOS accessories recommendation (I have an iPhone 7) I decided to get a Bad-Elf GPS Pro, I defined a track around my home and I can get it to work with no issues using the phone GPS but once I enable the Bad-Elf it doesn't seem to recognise the starting point and quite often I get alerts saying accuracy is not good (while the Bad Elf shows good satellite locks).

When I check the Sensor List I can see it but sometimes shows 10Hz but most of the times shows less than that (quite often 1Hz only).

Any suggestions? Am I missing any setup steps?

Thanks!!
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Harry
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Re: Bad Elf GPS Pro Issues

Post by Harry »

A drop to 1Hz usually means the BadElf is disconnected and the internal GPS takes over. This in turn is an indicator for the BadElf connection and will likely lead to missed laps. To troubleshoot, please make sure you identify all BT devices around and turn them off (including car stereo). Afterwards, check the general GPS operation using LapTimer's Sensor List (update rates and connection status) and GPS View (GPS accuracy). Let me know what patterns in accuracy and connect / disconnect you see.

Important: make sure you have no other app accessing the Bad Elf at the same time. It is best to kill other apps doing this and many access the GPS in background too.

- Harry
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widarecu
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Re: Bad Elf GPS Pro Issues

Post by widarecu »

Thanks for your reply Harry, appreciate it.


So I did a whole bunch of testing and finally got it to work but I still have a couple of issues left. Here my findings:

* When the phone GPS and the external GPS are both enabled and by some reason external GPS doesn't have good reception then auto start/stop doesn't work properly. I solved this issue by always disabling one or the other (I'm currently keeping the Location services disabled for Laptimer and then auto start and stop with badElf generally works ok)
* I found that having the BadElf app open at the same time with Laptimer was also affecting the update rates so now I close every single app and run only Laptimer

After those fixes I went to the track yesterday and had 5 sessions but in 2 of those sessions the auto start didn't work so I missed the recording for all those laps, this is what I can see:

* Constantly when I check the Sensor List, I can see BadElf shows as "connected" but no update rate and then a few seconds later shows only 1 Hz even though the gps has full sky view, to solve this I need to restart the app, and also the GPS a couple of times until eventually it shows back 10HZ (sometimes even more which is a bit weird). This is very annoying as I'm with my full gear (I use it on my track bike) so I can't really push buttons easily or move around to reach the bike tail to restart the GPS, any suggestions?
* In the cases the autostart didn't work I noticed the phone screen was locked when I finished the session, I guess it happened automatically after it was not able to find the starting point (my auto screen lock is set to 5 mins but my laps were 3 mins)
* Battery in my phone was around 45% left while the GPS was around 80% and no other apps were opened at the same time
* And additionally to that, the maximum speed in Laptimer doesn't match my bike which was telling me I was going 250+ kph but lap timer tells me 223kph (20 kph difference), is that normal or maybe related to the same BadElf / Laptimer synchronisation issue?

Any ideas?

Thanks in advance for your help!!
Dubbedown
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Re: Bad Elf GPS Pro Issues

Post by Dubbedown »

What's others experience with bad elf (with lightning adapter) so far? I need an external gps for an Apple device that doesn't get cellular and thus seemed like the most elegant solution. But based on the few posts I've seen here it doesn't seem the most reliable...
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Harry
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Re: Bad Elf GPS Pro Issues

Post by Harry »

As written before, LapTimer doesn't use the internal GPS while an external sensor is connected. So usually, there is no advantage to disable it. However, while the BadElf is connected, it will be hooked into iOS's location service (Mfi). This means if any app is using GPS, the Bad Elf will need to deliver data both to iOS and to LapTimer's direct integration. I need to ask the Bad Elf people if this can cause issues.

Running the Elf app in background can cause issues if it accesses the Bad Elf directly too. Actually it should stop activities when send to background, need to check that too.

LapTimer locks the phone when using one of the racing related screens (like Timer). This means that independent from your sleep settings, it will never go to sleep in Timer (until the battery is drained).

You need to use a power adapter please. Even for a new phone, an app like LapTimer will drain the battery fast. Using all sensors and doing processing requires lots of energy. Furthermore, when you get this low power alerts, the app will be interrupted and stop working.

Harry
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widarecu
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Re: Bad Elf GPS Pro Issues

Post by widarecu »

Dubbedown wrote:What's others experience with bad elf (with lightning adapter) so far? I need an external gps for an Apple device that doesn't get cellular and thus seemed like the most elegant solution. But based on the few posts I've seen here it doesn't seem the most reliable...
I have the Pro version (via Bluetooth) and so far not too happy with it, I got the external antenna bundle and it doesn't work (filing a warranty claim as we speak) and then I find inconsistencies in my speed readings. I'm thinking on changing it for the VBox or Push if I don't manage to get the badElf to work more accurate and reliable.

@Harry - thanks for your reply please keep me updated if you hear anything important back from badElf. About the misreadings at high speed (I'm doing 250+ kph but the app shows me 230 kph), Is that normal due the high speed or you think a problem with badelf?

Thanks
Dubbedown
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Re: Bad Elf GPS Pro Issues

Post by Dubbedown »

Harry wrote:A drop to 1Hz usually means the BadElf is disconnected and the internal GPS takes over. This in turn is an indicator for the BadElf connection and will likely lead to missed laps. To troubleshoot, please make sure you identify all BT devices around and turn them off (including car stereo). Afterwards, check the general GPS operation using LapTimer's Sensor List (update rates and connection status) and GPS View (GPS accuracy). Let me know what patterns in accuracy and connect / disconnect you see.

Important: make sure you have no other app accessing the Bad Elf at the same time. It is best to kill other apps doing this and many access the GPS in background too.

- Harry
Missed that part about killing any other GPS apps while running lap timer so ended up losing some gps accuracy, not big deal...

But my question is should we still run the GPS app initially in order to confirm the antenna has locked onto satellites (and then proceed to kill the app)? Or can we skip this entirely and just load up lap timer,and GPS will 1) automatically look for satellite and 2) it won't take any longer to do so compared to running the GPS app beforehand
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Re: Bad Elf GPS Pro Issues

Post by Harry »

widarecu wrote:@Harry - thanks for your reply please keep me updated if you hear anything important back from badElf. About the misreadings at high speed (I'm doing 250+ kph but the app shows me 230 kph), Is that normal due the high speed or you think a problem with badelf?

Thanks
The higher and constant speeds are, the better GPS speed accuracy gets. There is no relevant limit for GPS speed measurements.

- Harry
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Re: Bad Elf GPS Pro Issues

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Dubbedown wrote:Missed that part about killing any other GPS apps while running lap timer so ended up losing some gps accuracy, not big deal...

But my question is should we still run the GPS app initially in order to confirm the antenna has locked onto satellites (and then proceed to kill the app)? Or can we skip this entirely and just load up lap timer,and GPS will 1) automatically look for satellite and 2) it won't take any longer to do so compared to running the GPS app beforehand
No, you never need these manufacturer apps. Only exception: update firmware.

- Harry
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