Strange result with Health app.

[NSquirrel]

With ios11.4 the Health app seemed fairly accurate and our two iPhone 8’s gave very similar results, within 0.1 or 0.2 of a mile.

Today, with ios 12, we walked roughly 7 miles, as measured on a map. My wife’s phone was in her backpack and mine was in my front pocket, as always.

Her phone gave results of
Distance 7.5 miles
Steps 17,862
Flights climbed 3 floors

Mine gave
Distance 4.3 miles
Steps 10,936
Flights climbed 3 floors

I can think of no reason for the difference as we walked together the whole time.

Hopefully with this post are two graphs from the app showing how the distances have been recorded.

 

[NSquirrel]

Further to my post yesterday, I have ascertained the cause: it is bluetooth, which I only turned on last week for use in my car when going to collect some friends at Heathrow. (The clue came from the dots prior to the spikes and where they started, on earlier days than shown, which coincided with our going out by car, which was quite infrequent.)


Whether it occurred with ios 11, I now do not know, as I have almost never tried coupling the car system up to my iPhone. Also, as my wife’s iPhone is not connected to the car, which also explains why her results were seemingly correct to my incorrect.


The car, a Suzuki SZ4, uses a Garmin Infotainment sat nav, radio, phone control system.


What I am unable to tell is whether it is a bluetooth fault by Garmin or in the iPhone. If in the iPhone it maybe that the Health app expects any bluetooth data input connection solely from the iWatch, which I do not have. (Neither to I have bluetooth earbuds.) If related to coupling to the iWatch, this may explain why the ‘dots’ carried on for a day or two at a time rather simply ceasing when I stopped the car.


I will complete a bug report to Apple as it may affect others.