Re: APRSISCE on battery power


Lynn Deffenbaugh
 

Greetings Julian,

Outside of one thing, there's an explanation for everything (I think).

g4ilo wrote:
For some reason on my phone the "turn off backlight if device is not used" power saving option doesn't seem to work. The screen only goes blank after xx minutes when the "Turn off device if not used for xx min" option is enabled. This option appears to have the same effect as pressing the button on the top. When the device is off, it is still connected to APRS-IS and can receive APRS messages but GPS tracking is off. The only way to keep tracking while portable is to disable the "Turn off device" option altogether and not to switch it off when putting it in your pocket. However having the backlight on while the phone is in a case in my pocket is a waste of current and doesn't help the battery endurance any.
The "turn off backlight" setting does just that, it turns off the backlight. However, on my AT&T Tilt, depending on my brightness settings, there's not much difference between backlight on and off. However, it really does save power and it dims down the screen, but it won't go completely blank. The best way to see this it to keep the phone laying out and set the timer short. You should see the screen dim when the timer expires. Touching the screen in any fashion or pressing any of the buttons on the phone will turn the backlight back on. Even pulling the phone out of the case is likely to turn it on.

When I go portable, I keep the "Turn the device off" settings disabled and control the GPS (and subsequently power consumption and tracking) via the on/off button. Lucky for me, the on/off button is on the top where it is nearly (but not totally) impossible to accidentally push. I usually notice that the phone is turned on in my pocket (reminders will turn it on) when I get a warm spot on my leg.

Another way to save battery power is to turn the screen brightness down to the minimum. However, this makes the screen very hard to see and therefore hard to get it cranked back up to see it.

On the plus side, the battery drain was a lot less due to the fact the GPS was only activated when I took the phone out of my pocket to check it. In fact after 3 1/2 hours it was still showing 75% capacity.
Yeah, that's the best way to save battery, keep it off most of the time! (Just kidding). Just as a reminder, you can view your battery levels as telemetry like:

http://aprs.fi/telemetry/G4ILO-12?range=day

But for some unknown reason I would often find that APRSISCE had disappeared the next time I turned on the phone. One time it had tried to close after a message had been received and the only trace was a window called WM_CLOSE that said "You have unacknowleged messages." The program would not restart after this and I had to poke the phone with a stylus to reboot it. Another time there was a messaage about "Odometer failure." Other times it vanished without trace. The only times the program kept running were when I pressed the button on the top to switch off the phone before slipping it into its case and putting it in my pocket. Because it was in quite a stiff case I don't think anything could be pressed to close the application while the phone was in my pocket.
The only two ways I've had that APRSISCE "disappears" is 1) an inadvertent click on the X (likely, especially given the unacknowledged messages" popup and 2) bringing another app up over top of APRSISCE (like the today screen). In the second case, simply re-activating APRSISCE brings it back to the foreground. You can tell the difference between a new copy and a restored copy by the absence or presence (respectively) of stations in the scrolling station list.

The current version of the program does appear to hang for up to 90 seconds at a time when you lose data coverage. Regardless of what dialog is displayed (like the Odometer failure which is caused by the loss of the APRS-IS connection), if the program is attempting to establish a new APRS-IS connection, it will "hang" for a while and be non-responsive to clisk.

However, even in that case, you should NOT need to reboot your phone. Simply go to Start / Settings / System / Memory / Running Programs. Click on your callsign (or APRSISCE or whatever looks like the client in that list) and click Stop. There will be a delay and then Windows Mobile will tell you the program isn't responding at which point you can kill it. After doing so, I use Internet Explorer to verify a good data connection and then restart APRSISCE.

The next version (as soon as I get it finished up) will not exhibit this hang during connect but will remain responsive enough to at least communicated that it has lost the APRS-IS connection. Reconnection will continue to be automatic, it just won't hang the user interface while doing so.

Lynn (D) - KJ4ERJ - APRSISCE as -12, APRSIS32 as -15, -AP and currently IGating as -1

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