Selene | # 1 | 2014-03-24, 12:26 | Report

Dawn simulation is a technique that involves timing lights in the bedroom to come on gradually, over a period of 30 minutes to 2 hours, before awakening.
http://en.wikipedia.org/wiki/Dawn_simulation

There are likewise apps for iphone/android:
http://appcrawlr.com/app/search?go=g...=ipad%2Ciphone

I was thinking it would be nice to have such an app for maemo, using the camera leds. Would anyone like to try this?

gianko | # 2 | 2014-03-24, 19:12 | Report

is it the N900's camera led dimmable( increase/decrease light intensity)?

pichlo | # 3 | 2014-03-24, 21:22 | Report

There is a long discussion over in the Lanterne thread about what the N900 flash LED can do. In a nutshell, yes, it is dimmable (in steps; 8 or 32 depending on mode).

There is also a long discussion in the same thread whether it is a good idea to leave the LED on for any extended period of time. I personally would not risk leaving my LED on for "30 minutes to 2 hours", although the idea is not as crazy as it souds. I've just tried it: it is dark here as I type this and the LED seems bright enough to be actually useul for the purpose.

Selene | # 4 | 2014-03-24, 21:56 | Report

I am not a programmer or a technical expert so I can't answer those questions.

If you take a photo with the camera app the leds seem less bright when focusing compared to the "photo flash".

If dimming is not a good idea, there are still possibilities.

For example, turn on the screen 30 minutes before the alarm, fullscreen red->orange->yellow->white with increasing brightness, and 10 minutes before the alarm turn on the camera leds. Of course, for this you would have to place your N900 on the backstand on a white surface.

Estel | # 5 | 2014-03-25, 02:22 | Report

Wow, I haven't though that someone not participating in mentioned Lanterne discussion/hecking sources would notice that. Respect

In a nutshell, indeed, there are two modes. The "basic" one, as used for all torch applications, got lesser maximum brightness value (due to lesser current), but is able to perform 100% duty cycle (aka "just be turned on"). The "flash" mode is much more powerful, but available only in duty cycles (with maximum one around 75% IIRC, but don't quote me on that - details in the already mentioned Lanterne link provided by pichlo), and rightly so, as using it on 100% would damage leds pretty quickly.

Now, for the purpose of program proposedd here, only the "torch" mode is approriate, as I don't think that stroboscopic effect is good for a healthy sleep/awakening (unless someone want to simulate dawn in a hurricane-hit forest, with light passing through shaking branches/leaves).

Why? "Dimming" (to be precise, changing current in a steps, in our case) is neutral for a diode. AIUI [/b]pichlo[/b] meant leaving flash diodes turned on for a prolonged time, no matter what the brigtness level.

Here I disagree, BTW - my trusty N900 is helping me with various conservation tasks in not-so-easily-accessible places for years already, and I regularly leave flash diodes at maximum "torch" mode brightness for a hour or so, as it's lighting up my patient's internal organs workplace. Zero adverse effects observed - in fact, I've actually had some unpleasant surprises with other hardware components, and I guess that those leds (and their backscreen/keyboard counterparts) are the things that will be (amongst) longest living parts in N900's motherboard, no matter of (ab)use.

/Estel

// Edit

In fact, what you would like to achieve could be done with a rather simple script (written with help of Lanterne discussion and its documentation), executed by any alarm app that can trigger custom command on alarm.

Executing command on alarm would be, probably, a few lines of code in CSSU'ish alarm replacement (or update, I don't remember if it was open thing in vanilla). IIRC, freemangordon was the author of CSSU'ish latest version - it could be good idea to post a feature request in CSSU's bugzilla. If that part is done, you have 99% of work done.

/Estel

Otherwise, there should be, already available, "eggtimer" programs that can trigger custom commands, but setting them up for alarm clock job is more tedious (and less "clean") job than using Maemo's integrated alarm would be.

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Last edited by Estel; 2014-03-25 at 02:29.

pichlo | # 6 | 2014-03-25, 06:26 | Report

Correct. Please note that I did not express my personal opinion, only said that there are different opinions and pointed out the thread.

Yeah, cron and alarmed come to mind.

Selene | # 7 | 2014-03-25, 21:20 | Report

Thanks

I agree integration with the CSSU Alarm clock would be a good option.

Sorry I misinterpreted your post.
Are there any known cases of failed camera leds on the N900?

If someone is willing to write the code for this feature I'm willing to risk my leds and will report if they still work in a few months.

Estel | # 8 | 2014-03-26, 04:06 | Report

As far as my notorious TMO'ing knowledge goes, it's exactly 0 cases. (which bring it the same as confirmed... Blast "confirmed", in fact "even-remotely-plausible" cases of overclocking damage. But that's totally different thing). Unless someone torn apart secondary's board flex cable, but then, diodes are least of the problems.

/Estel

sixwheeledbeast | # 9 | 2014-03-26, 13:32 | Report

The main flaw in this is having to have the Lens cover open and the device screen down.

This could help you, step by step instructions on setting up a Internet Radio Alarm Clock that slowly increases volume.
http://talk.maemo.org/showpost.php?p...7&postcount=10

Selene | # 10 | 2014-04-02, 20:34 | Report

I don't really see a problem with that? Unless your nightstand is made of concrete..
You could also put it on the backstand or make some kind of docking station, aiming the flashlight at at white wall.

Thanks, but my programming experience is 0.0 and I just recovered from RSI enough to browse the internet a bit so starting now is probably not a good idea.

I just made this thread to see if there are more N900 owners with trouble getting up in the morning (and hopefully someone capable of making such an app)