Alan, thanks for your two messages. II’m doing most of what you suggest (not using accuracy so far, but the prudent person probably should do!), but nevertheless I would like to emulate my fitness app example. I have apps that positively know when they have acquired a meaningful GPS signal, whereas the methods i’m using contain an element of chance or guesswork. I want to completely eliminate that.
In practical terms, I can’t start the sensor until the user needs it, because of battery drain - you will find this in most trekking and fitness apps - one is more or less confined to a button ‘Start’ or something similar. At that point, my ideal would be to show the user that I’ve started the sensor acquisition and tell them when it’s succeeded or failed. I feel it has to be possible, but perhaps not with LC. Graham > On 26 Apr 2020, at 02:47, Alan Stenhouse <alanstenho...@hotmail.com> wrote: > > Hi Graham > > Some ideas, from experience: > > 1. Start your sensor on openStack or as soon as possible. > > 2. Ignore locationChanged messages with empty location or if "horizontal > accuracy" is outside a threshold of x metres. > > 3. Just set a flag or other mechanism when you want to start and stop > tracking which indicates to your locationChanged handler to record or stop > recording the track. > > Hopefully that sounds reasonable? > > cheers > > Alan > >> On Sat, 25 Apr 2020 14:07:01,Graham Samuel <livf...@mac.com >> <mailto:livf...@mac.com>> wrote: >> >> >> Typical fitness apps (such as iCardio by FitDigits) can read various >> sensors including a Heart Rate Monitor via Bluetooth, and one?s location via >> inbuilt GPS. When you start an activity like a run or a workout, the app >> goes through an acquisition phase, and won?t start recording until the >> sensors are functioning. This is made clear to the user by a display. >> >> I want to do this in my LC iOS app, specifically for the GPS. I know how to >> start the location function on the device and I know how to handle the >> position via ?locationChanged' and/or ?mobileCurrentLocation', and these >> work. The big problem is at the start of such a sequence. I can use >> 'mobileStartTracking Sensor ?location? ? to get going, but experience shows >> that this takes an unpredictable amount of time, sometimes of the order of >> seconds. You would think that the locationChanged messages wouldn?t start >> firing until the start tracking process had done its job, but it seems this >> is not so, and nonsense locations can appear at the beginning of the >> sequence. At least that?s my experience. >> >> I am loth to use a loop to see if the tracking is really started and legit, >> and anyhow this would be problematical if my app was being inundated with >> ?locationChanged' messages while the loop is running. >> >> Has anyone any experience of this issue? As usual, I feel I?m missing >> something. Perhaps the ?trackingError? message might help, but I don?t see >> how. >> >> Graham > _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
