Harry's GPS Suite Forum

I've been very happy with the mount for my iPad Mini's that I have rigged up rigged up:
But the owner of the track where I drive doesn't like the fact that it's in my direct field of view, because he's afraid it could be a distraction, and asked me to move it to a different location. I don't find my current location distracting at all, but he's the boss (he's actually a very nice guy), so I have no choice but to move it. Here's the best option I've come up with for having it out of my direct field of view, while satisfying the accelerator's requirements to give static lateral and lineal readings near zero:
Sorry about the blurriness of the image; the first one was taken in much better lighting conditions. As you can see, it's in the rightmost corner of the dash. I can tilt it to get the acceleration readings near zero in preset mode, but on page 4 of the document that covers acceleration measurements, it says, " LHT / RHT presets assume you have the phone mounted in the windscreen centered horizontally (i.e. not near the A-pillar) pointing to the driver with an angle of 25 degrees and with a slight tilt of 5 degree." Getting the ipad out of my field of view puts it very near the A-pillar. Is this OK, as long as the static acceleration values are near zero? If not, do you have any other recommendations? Thanks.

Upon reflection, I suspect the track owner may not like my proposed location, either, because while it's not in my direct field of view, he'll probably say there's too much temptation to turn my head to look at it. So, as an alternative, is there any reason I couldn't attach it the the front of the passenger seat where the holes for the shoulder straps go through? This would actually put it higher than where's it's mounted now, and I checked the static acceleration numbers, and they're very close to zero.

I agree, the right position (or anything beyond the center of the car) is good due to the addition time required to turn the head and refocus. You can use orientations different to the presets. This option is named "individual calibration" and described in Acceleration Handling available from www.gps-laptimer.de/documentation.

Why not lowering the iPad's position and keep the current mounting otherwise? Directly in from of the fans?

- Harry

I was going to go through the individual calibration procedure, but went ahead and tried preset mode first, and saw that I could easily get the static acceleration numbers near zero with the ipad against the passenger seat where the shoulder strap holes are located. Do you think there would be further benefit using the individual calibration procedure?

And I agree that lowering the unit where it is currently located could be another option, but I thought it was best to have the unit as high in the car as possible. Is this not correct?

For GPS reception a center position (horizontally and vertically) is best.

- Harry

I don't think the iPad mini has GPS, mine doesn't, so GPS reception is not an issue with mounting.

I'm using an external GPS, which I have mounted to the top of my dash. So if I understand correctly, the mounting location of the ipad only impacts the accuracy of the lateral and lineal acceleration readings. Given that, does it matter where my ipad is located, as long as the static acceleration figures are near zero?

With an external GPS, the position is irrelevant with respect to sensor readings (except orientation if a preset is used).

- Harry

Thanks. But it's still important that the static acceleration figures read near zero, right? It must me, because I rode for a few laps in a friend's car once, intending to collect data with Laptimer. I placed by XGPS160 on top of his car's dash, but, because I hadn't yet read the documentation, I just stuffed the ipad down next to the seat, and the lineal and lateral acceleration readings from his laps were pure gibberish.

Yes, acceleration measured are always oriented in the device, not driving directions. Either you use one of the presets and comply with the orientation requested (illustration #4), or you set up an individual calibration. It will never be irrelevant how the device is orientated. For laps recorded with screwed up acceleration, you can calculate acceleration from GPS. Select any lap from Lap List, press Recalculate ‣ Acceleration to replace measured by calculated acceleration.

- Harry