Counting seconds in a datafield

This topic came up a couple of times in the past, and there were multiple ways people do it. One of them is also what I did in some data fields, i.e:

hidden var mBatteryStatusBlink as Number = 0;

onUpdate(dc) {
    mBatteryStatusBlink += 1;
    if (mBatteryStatusBlink % 2 == 0) {
        dc.drawBitmap(x, y, batteryStatusIconDrawable);
    }
}

In the simulator it blinks once per second as I thought it will, and also on 2 of my 3 real devices I tested.

However to my surprise on real fenix6 at the beginning (before I start the activity and for the 1st 10 seconds of the activity) it blink something like 5-10 times a second. I think the reason is that next to my DF I have a built-in timer field, that counts the time in "hundreds" of seconds for the 1st 10 seconds (which interestingly the fr965 and edgeexplore2 don't do).

So I guess the better way is to save the timestamp and compare it...

Top Replies

peterdedecker 11 months ago in reply to _psx_ +1

_psx_ said:
You can count it simple in compute()... It should be called every second

it's not, I've seen it skip seconds.

All Replies

peterdedecker 11 months ago

onUpdate can trigger a lot more than once per second (whenever the watch feels screen updates are required, for instance showing message overlays) and it could also be slower than once per second (if you have a lot of calculations)

flocsy🤠 said:
So I guess the better way is to save the timestamp and compare it...

absolutely.

_psx_ 11 months ago

You can count it simple in compute()... It should be called every second

flocsy🤠 11 months ago in reply to _psx_

maybe, but I am blinking a battery icon when the HRM's battery is critical, so I do it in onUpdate. But I have now a better solution:

if (Time.now().value() % 2 == 0) {...}

mcinner1 11 months ago in reply to flocsy🤠

I have a „blink timer“ in compute() on my Edge datafields which sets a global blinkflag true/false. This flag can be used where ever it is needed.

peterdedecker 11 months ago in reply to _psx_

_psx_ said:
You can count it simple in compute()... It should be called every second

it's not, I've seen it skip seconds.

_psx_ 11 months ago in reply to peterdedecker

Nobody looks on watch all the time :-)

_psx_ 11 months ago in reply to flocsy🤠

getClockTime().sec can be faster and takes lots memory

FlowState 11 months ago in reply to peterdedecker

peterdedecker said:
it's not, I've seen it skip seconds.

Yeah I think this happens under high CPU load or something (or as you said, if you have a lot of calculations)

FlowState 11 months ago in reply to _psx_

_psx_ said:
getClockTime().sec can be faster and takes lots memory

While we’re discussing alternatives, how about System.getTimer() / 1000. (Yes it rolls over, but I think it’s ok for this use case of doing something every other second — i.e. if ((System.getTimer() / 1000) % 2 == 0) …)

EDIT: fixed bad math

jim_m_58 11 months ago in reply to _psx_

in a data field, elapsedTime or totalTime, give you ms, so easy to convert to seconds