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? DM42 as Alarm Clock ?

Posted: Mon Jul 22, 2019 5:17 pm
by TomC
Hello:

Apologies if this has been covered already.

Can the DM42 be used as an alarm clock - ie waking me at 530am every weekday morning?

(I use my HP48 quite regularly for this and was hoping the DM42 is able to !)

TIA
TomC

Re: ? DM42 as Alarm Clock ?

Posted: Tue Jul 23, 2019 4:37 am
by grsbanks
I'm afraid not.

Many of the functions in the HP-41C Time Module were ported to Free42 but sadly, alarm functions are not among them.

Re: ? DM42 as Alarm Clock ?

Posted: Tue Jul 23, 2019 4:47 am
by TomC
Thanks for the reply.

Is there a hardware limitation?

TomC

Re: ? DM42 as Alarm Clock ?

Posted: Tue Jul 23, 2019 7:28 am
by ijabbott
It's probably technically feasible on the DM42 from a hardware point of view (using the STM32's RTC alarm capabilities), but probably a lot of effort from a software point of view.

Re: ? DM42 as Alarm Clock ?

Posted: Tue Jul 23, 2019 9:27 am
by Thomas Okken
My main reason for not having implemented the alarm clock features is that they are difficult or impossible to do properly in a desktop app. The main problem is that applications are not always running, so Free42 would have to install a helper of some sort to launch or raise it when an alarm comes due. And there's nothing it can do to support alarms that come due while the computer is off.

On Android and iOS it may be possible to implement alarms in a way that is usable, but I confess I haven't looked into that. On iOS at least, I believe it is not possible for an alarm to launch or raise an app, but it could show a message box that offers to do so. It is not clear to me what the added value of that would be, compared to using the iOS Calendar or Clock apps directly.

On the DM42, emulating the Time Module / 41CX Alarm functionality would make more sense, and it could be done well, but for Free42 on other platforms, I just don't see it.

Re: ? DM42 as Alarm Clock ?

Posted: Tue Jul 23, 2019 10:09 am
by Pekis
Hello Thomas,

On Android, I found a reliable way to program alarms, with my multiple Stopwatchs/Timers app interacting only with the Google Clock App, so it could bypass my Huawei battery-saver, even with screen off (but not shutdown).

Anyway, IMHO, it clearly should be implemented in DM42.

Thanks.

Re: ? DM42 as Alarm Clock ?

Posted: Fri Sep 13, 2019 6:18 am
by Geoff Quickfall
The alarm function not the HP41 was really for HPIL control. Set flag 11, turn off calc and when alarm wakes calc up, execute resident program.

Mine woke up, turned off some lab equipment and turned some on back in the early 80s via HPIL.

42s was not a controller; no HPIL, so no need to implement time functions (reduced budget interfered with the HP42 S design) also.

Alarm made a comeback in the stretch pioneers of course.

Yes, I would like to see alarm functions implemented.

Cheers, Geoff

Re: ? DM42 as Alarm Clock ?

Posted: Fri Sep 13, 2019 9:51 am
by akaTB
Geoff Quickfall wrote:
Fri Sep 13, 2019 6:18 am
The alarm function not the HP41 was really for HPIL control. Set flag 11, turn off calc and when alarm wakes calc up, execute resident program.

Mine woke up, turned off some lab equipment and turned some on back in the early 80s via HPIL.

42s was not a controller; no HPIL, so no need to implement time functions (reduced budget interfered with the HP42 S design) also.

Alarm made a comeback in the stretch pioneers of course.

Yes, I would like to see alarm functions implemented.

Cheers, Geoff
But they were present in 27S and 17B, I think.

Re: ? DM42 as Alarm Clock ?

Posted: Fri Sep 13, 2019 10:54 am
by Boub65
Hello,
1) I understand that Free42 has some instructions enhancements to the standard HP42s instruction set (date and time, base enhancements, LSTO local variables, etc...)
2) I understand that Free42 has some platform dependent instructions (accelerometer, GPS and compas)

so...

I really don't understand why Free42 couldn't support 1) Alarm instructions enhancement to HP42s AND 2) DM42 plateform dependent instructions ?
Sorry... but I really don't understand...
EDIT: except if it is technically impossible...

Boubker.

Re: ? DM42 as Alarm Clock ?

Posted: Fri Sep 13, 2019 12:01 pm
by Thomas Okken
It is impossible, because Free42 is just an app. It doesn't control the hardware.

On an HP-41C with a Time Module, or an HP-41CX, or a hypothetical DM42 with updated firmware, an alarm can turn on the calculator. Applications running on Windows, MacOS, or Linux have no such capability. Apps running on Android or iOS may be able to set alarms through those platforms' native calendar or alarm clock features, but still wouldn't be able to schedule programs for execution.

These limitations explain most of the Time Module functionality that is missing in Free42. The rest has to do with setting and calibrating the clock, which is impossible and unnecessary, respectively, on the platforms Free42 supports.

The DM42 doesn't have these limitations, and there is no reason why the full set of HP-82182A or HP-41CX alarm and clock functionality couldn't be implemented there, but if that is going to happen, it will have to be done by SwissMicros themselves, or by a contributor working specifically to target the DM42 platform.

The one piece of missing time functionality that I might still implement in Free42 is the stopwatch. Maybe after all the dust has settled from the latest round of changes...