Took a look at my data files and getting about 10hz from GPS, but only 3hz from OBD. Although resolution is better with GPS the video speedometer is NOT as smooth as OBD. Is this due to inaccuracy of GPS? The discrepancy can be fairly large at times. I'm guess OBD is more accurate despite the 1/3 resolution?
And speed data in app seems to be GPS... anyway to choose OBD?
I think trackaddicts is awesome!!! Can't wait for the best theoretical lap feature
OBD better for sure during periods of rapid accel or braking. how many OBD params are you logging? If you cut those back, the rate will increase. I get 5-6hz logging RPM, vehicle speed and throttle on a 2003 Z06. Your phone/bluetooth adapter may slow down/speed up the speeds as well.
I'm logging same as you... mph, rpm, and throttle. Using iphone 6S... vid from phone, XGPS160 + BT1. I'll check if I missed a setting, but maybe my combo is just slower.
2001 coupe
I have android samsung galaxy s7 with obdlink MX + XGPS160. I thought wifi was the preferred method for iphones? I dont find throttle parameter to be all that helpful (since its throttle position, not accel pedal position) and my exhaust is plenty loud so i can hear it in video
I find myself switching between displaying GPS speed or OBD speed depending on the circumstances... When GPS reception conditions are good and you have a fast responsive GPS, the GPS speed tends to be the most reliable and accurate, as it wont be affected by wheel spin, tire size error, turning, and wont max out at 158 MPH (OBD speed via the standard SAE parameter is limited to 255 km/h). TrackAddict does its statistics and other calculations based on GPS speed for those reasons. However, GPS is of course sensitive to reception conditions (you really want a good line-of-sight to a large area of the sky, no metal above it), and the responsiveness of the GPS speed can still be limited and/or have a slight delay. I would suspect there may be some level of filtering being applied to the doppler speed calculation that's taking place inside the GPS unit. The XGPS160 and 10 Hz Qstarz units tend to do pretty well with this, but they still may not be as responsive as a sensor attached to your powertrain, and some other GPS units have been known to be much more laggy.
It started that way, but fortunately there are now a few OBD device manufacturers who have made it easier for 3rd party apps to work via Bluetooth on iOS:Originally Posted by aaronc7
GoPoint BT1 / BT1A - works via proprietary Bluetooth on iOS (not supported in the Android version at this time)
PLX Kiwi 3 - works via BLE on iOS (not supported in the Android version at this time)
Carista - works via BLE on iOS, standard Bluetooth on Android
iOS still can't use the standard Bluetooth devices (restricted by Apple), of which there are many that we're able to support in our Android version, but the above iOS options tend to work pretty well for iPhone users.
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