GPS device for iPhone 5

[limpabit]

Hi everyone.

I've got the iPhone 5 with Ram Mount. Very happy with the stability when on track.

But now looking at external gps devices. I like the idea of the Emprum device being all in one and compact. But don't look like it will fit.

What options do I have? BT XGPS150 or such devices?

[Harry]

Three good options...
Emprum Ultimate GPS + Lightning adapter (5 Hz)
Dual XGPS 150 (5 Hz)
Racelogic VBOX Sport (20 Hz)

The VBOX unit will be at a different price point however - available in March.

- Harry

[limpabit]

Ah that's great thanks Harry. Was not sure if the Emprum etc would fit in the Ram Mount. That's great news.

[limpabit]

Hi Harry.

Just ordered the Emprum

How does it all connect together with the RAM Mount? Connect lightning adapter (there's also a lightning cable) to the phone, fit into the RAM mount? Or use lightning cable from phone to Emprum then to charger to charge battery?

[Harry]

Firstly, I hope you have requested your 10% discount (check Harry's LapTimer -> Tracks -> Ultimate GPS Discount). The Ultimate and the RAM Mount are actually not connected, you add your iPhone5 to the RAM mount and simply plug in the Emprum using one of the Lightning adaptors (both should work). In addition, you attach a power supply to the Ultimate and connect it to your car's lighter plug. Although the Ultimate works without, the power connector will charge both the GPS dongle and the iPhone.

- Harry

[limpabit]

Hi Harry.

Thanks for the information. I'm looking forward to having a play when it arrives.

Unfortunately, I missed the 10% discount Already paid for now and in transit.

[achichon]

which are more accurate? the 5hz? or 10hz? or 20hz? harry ?

thanks

[Harry]

Update rates are not directly related to accuracy. I plan to perform some side by side tests for the Dual, the VBOX, and the internal GPS in the near future. Looking into position accuracy claimed all sensors in scope (except the internal one) are at around 1 to 2 meters once a DGPS lock is available.

- Harry

[achichon]

oh I see, so the 5,10,20 hz are the 'refresh rates' ??

[Harry]

Yes, the number of positions acquired per second. High rates are good to get smooth lines and better understanding of min / max points (e.g. braking position). On the other hand, high rates put higher load on the system which in turn may lead to other problems (like lost satellite locks, missing DGPS).

This means you need to see the sum of several dimensions to judge a sensor:

1. Update rate (# of position per second)
2. Accuracy delivered (accuracy of individual positions)
3. Lock stability (low stability means to get drop outs, i. e. missing fixes when receiving condition get difficult)

Just to give an example: both XGPS150 and UltiMate deliver 5 Hz at very high accuracy - but they loss the lock regularly in a difficult turn on my home track Nordschleife (namely "Bergwerk"). Opposed to that, the older TomTom car kit delivered only 1 Hz and high (but nbot very high) accuracy, but NEVER lost the lock in this turn.

- Harry