Re: Using the N900 as a complete desktop replacement, is it possible?
 

Something like this?

I don't think the N900 can do that in an acceptable manner. Android is getting closer with each release. Maybe if Maemo was continued... But that's another story.

Re: Using the N900 as a complete desktop replacement, is it possible?
 

Using kernel-power and Pali's BME replacement bits (or even without them, but then you need to execute some scripts manually), you can have USB 2.0 hub connected to N900, <whatever> number of devices connected to that HUB, and N900 charging from USB - all at the same time.
---

Generally, using N900 as desktop computer is no problem - I do it all the time (as a travel notebook/desktop replacement, but still). Maemo does it since ages, and doe it *much* better than things from that video, or any android toy is/is going to.

Personally, I use USB keyboard *and* USB mouse, handled by extkbd and extmou packages, respectively (this way, you don't need to stick for some over-priced brands, you may use whatever you want, and generic ones are going to work perfectly). N900 is connected to flat TV's via video out.

The last part is bootleneck - there isn't problem with 800x480 upscaling, that would be still ideal. The problem is, that video out does *downscaling* to PAL or NTSC, which is main reason for blurriness (be sure to use PAL when available, it have slightly better image quality, due to more lines).

One of things that I finally need to set up "someday", is making a nice travel body for my Raspberry Pi, and, paired with N900 via USB networking, using it as HDMI video out for Easy Debian (at any resolution we feel fancy, even monitor/TV native ones). It all works perfectly well - there are just some glitches with USB keyboard, as extkbd *still* isn't working well with xephyr, so no good external keyboard mapping inside Easy Debian's LXDE (freemangordon, I'm looking at you). One could workaround it by installing bt-hid-scripts package everytime one want to have xephyr and external keyboard, then revert back to extkbd afterwards, but it is a PITA.

/Estel

Re: Using the N900 as a complete desktop replacement, is it possible?
 

Yes, you are right. Estel confirmed this is a possibility.

Re: Using the N900 as a complete desktop replacement, is it possible?
 

Something like that. I am willing to put up with the lower resolution / blurry text, that's not as much of a big deal to me. But I would like bluetooth keyboard / mouse, and ideally a bluetooth keyboard with integrated pointer.

On a different note, while that video is interesting, it makes me realize how ugly and chaotic Android is compared to Maemo. Ugh...
No offense if you are an Android user, just my honest opinion. Maemo is what somebody might call a much more "orthogonal" design. Android, from a design point of view, to me looks like the product of a mad chimpanzee on acid given full regin in Google's laboratory for insane scientists. :)

Re: Using the N900 as a complete desktop replacement, is it possible?
 

Thank you for confirming that. Do you think it would be possible in the future to be able to use the N900 connected directly to AC without any battery? That's another of the things I hope are possible.

I suppose that would be fine, now that I know it's possible to charge the N900 at the same time that it communicates with the keyboard and mouse through the same USB cable, by using Pali's code. Hmm... somehow I didn't realize how amazing it is you can do that until I spelled it out explicitly in a sentence.

I might dedicate one of my N900s to be used like this. I like the fact that it wouldn't be necessary to connect / disconnect the N900 from USB often, as connections would take place on the other end of the hub if necessary. It plays well to one of the N900's weaknesses (the tendency for the USB connector to break).


Wait, but NTSC is 480 vertically, just like the native resolution of the N900, isn't it? I honestly don't get how upscaling to 576 (PAL) helps, but I do believe you. I just don't understand how that would help.

I didn't know it would be possible to achieve (kind of) arbitrary resolutions from Easy Debian through the Raspberry Pi. Do you use it often? Isn't there a bandwidth problem to achieve a reasonable frame rate at higher resolutions? Anyway, that is very impressive.

Re: Using the N900 as a complete desktop replacement, is it possible?
 

Sadly, no :( AFAIK, it's hardware limitation, of how charging chip behaves. It *can* run N900 from AC without battery inserted in so-called emergency mode, and that was abused to Proof-of-concept hotswap of battery, but it require turning everything off and dimming screen. It just won't give enough juice to device itself, for any normal operation.

A way to achieve this, would be:
a) build a dummy battery, which is just <any_material> brick and "battery" pins connected to ~4.1 power source (+ 100kOhm resistor between BMi PIN and ground - the easiest way, would be to just cut off a PCB from any real N900 battery, and [ab]use it). N900 would just think, that it's connected to battery, that never runs out ;)

I'm perfectly sure, that it's the way N900 were powered at Nokia labs - BMI sense probe have even a certain identification range, that tells device it's running from dummy (just a curiosity, not important for us in any case).

Only drawback for this scenario, is that you may find hard to find uncommon ~4.1 power source. Dirty hack to achieve it, would be to connect normal 5V charger through a series of diodes, until it drop to ~4V (or even less, for safety margin), but you would want to test thoroughly how redundant voltage drop is (depending on temperature, moisture, etc) - unless you consider smell of fried chips at the morning a beautiful thing ;) In such case, I would even go for 3.7V target voltage, for safety margin (I don't think that voltage would ever1 change from 3.7 to above 4.2 or under 3.3, even at wide amplitude temperature changes).

b) Hacking together a very slim (DIY) PCB, that would like a middle-man between battery and N900, having own, low capacity (lets say, 100 mA) LiIon battery, and hardware switch, making it to run from either normal battery, or build in one. This would allow for real hotswap on the field, no matter of load device is actually on, and it's one of my "to do sometime in future" projects. There is no reason, why it couldn't have a input port for running from 4.1V DC power source, directly, or even a build-in 5V-> 4.1V converter (eliminating need for specialized, uncommon voltage power source). such converted would be, for sure, much more redundant than any "series of diodes" thing.

But, for sure, even flattest of custom PCB's would require mugen-sized cover. I can't imagine putting it under normal cover, until you own a manufacture that prints sophisticated circuits on a ultra-thin layer ;)

Be sure, to check thread about reinforcing USB port. It's quite easy process (if basic caution rules obeyed), and almost ensures no USB port-related problems.

But horizontal resolution is 720, so if you're using widescreen output (most likely case, as you probably doesn't want to have distorted proportions of programs displayed from N900 - still, N900 TV-out also allows 4:3 output), it goes some mumbo-jumbo with conversion, and practical result is, that you just want higher resolution output possible ;) Also, "resolution" in terms of video out is just a simplification - in fact, it does interlaced lines, so it work a little differently than one would expect. I must admit, that N900 does awesomely good work at conversion, and result is much higher quality, than most devices with video-out offers. Still, it's nothing, compared to having HDMI output :(

I've done tests- using flat TV, that accept both PAL and NTSC input - and PAL from N900 looked slightly better in all cases. Of course, I can't guarantee it to be the same on other monitors/TVs, so you're encouraged to do own tests. Also, I must admit, that difference is hardly noticeable (you need to look for it, preferably through using reference/calibration images, to see it).

See this thread:
http://talk.maemo.org/showthread.php?t=81408

(solution for Easy Debian is somewhere in middle-to-end posts, but I think it's worth to read whole thing, to get better picture). Sadly, I'm not using it often, due to mentioned problems with extkbd in LXDE (Xephyr) *bugs freemangordon again*. But, it is indeed impressive, and 25/35$ (depending on version) for a RPi for that purpose isn't too much (not to mention, that RPi can do many other things, too).

As for bandwidth - you're using USB Networking, so N900 can be in both client *or* hostmode. If you're using Pi as host and N900 as client, there are 0 problems, no matter of resolution output (up to FullHD 1080p). If you're using N900 as host, thing *may* look differently - our hostmode isn't ideal implementation, as practical transfer limits are around 4 MB/s (that is, *lower* than WiFi!). Still, in practice, I haven't seen any problems - using different X video output is very efficient. Keep in mind, hoever, that I haven't tested it so much as N900-as-client scenario.

Now, if you're using N900 as client you can't, obviously, connect client devices (keyboard, mouse...) to it - it can't be client and host at the same time. But, you can connect those to Rpi, and stream input to N900'sMaemo ;) Crazy, but works. If one would took effort to compile some FOSS USB-over-Network tools for N900, it would be, probably, possible to stream, *any* USB device connected to Pi back into N900, eliminating need for (physical) hostmode on N900 itself, as those tools create a "virtual" USB root hub. You would still need modules on N900's kernel side, though (just like now). OTOH, HID devices (keyboard, mouse, again...) doesn't need streaming USB protocol itself, you may just forward input devices at higher level.

Generally, possibilities are endless :)

/Estel

//Edit:
Added more info about RPi scenario.

Re: Using the N900 as a complete desktop replacement, is it possible?
 

That is too bad. I thought it might be possible. My thought was the following: It takes around 3 hours to charge a battery to full capacity. Also, even if you run an N900 as hard as you can (max screen brightness, WiFi, 3G, Bluetooth), most likely the battery will last more than 3 hours. Therefore, the USB port should be able to supply enough power to operate the N900 without a battery.

Now, I can imagine that the electrical circuit from the USB port to the battery is not the same as the circuit from the USB port to the mainboard, so maybe this theory is incorrect.

And, if they have truly crippled this possibility in the hardware (as you say, and I trust you), then this conversation is moot. One thing I like about my Zaurus SL-C1000 (I don't know if you are familiar with it, just a Linux PDA from a few years ago produced by Sharp in Japan) is that it can be operated without battery (although if you try to use the CF card port under those conditions, it will shut down).

Yes, that's a great idea! And I'm sure it's doable. It would be nice to get somebody in China interested in the business of virtual batteries. I hate for devices to became obsolete when their perishable power sources die and become unavailable.

It's interesting that this was the way N900 was powered in the Nokia labs, thank you for sharing that.

As for the difficulties in getting something like this to work, it's one of those things that you wish some manufacturer actually got interested in, as I said earlier. Put some R&D into it, come up with a solid reliable product, mass produce it, and profit. Win/win situation.

Yeah, I'm familiar with that thread, and I might actually give it a shot on one of my N900. I've been very careful since I got the 2 N900 which I have in use. I filed the retaining hooks of the USB charger (and USB data cable), and I make sure to always keep the N900 charging on its own in a different room, away from potential accidents. When you follow those rules I think it's unlikely for the USB port to break, but it can never hurt to reinforce it.

I understand. I thought horizontal resolution wouldn't be as important. I agree the N900 does a very good job putting out that analog video signal through the headphone out plug. It is surprisingly good, even projected to a large size. Not HD obviously, but very clear and usable.

I will make sure when I look for an LCD TV to use with the N900 to get something that can take a PAL signal. The TV Out Control Desktop Widget is awesome, and allows to change the output between PAL and NTSC easily.

I had seen that in your signature, but I haven't taken the time to go through that thread yet. I'll make sure to do that soon. Getting 1080p with the N900 as client is crazy, certainly not something I would expect


I had to read that twice. So you are saying that the N900, connected as a client to the Pi, can access other devices connected to the Pi via USB? Or, I guess, you put it more like "the Pi can route the input back to the N900", which I guess is a little less shocking, but still! :)

Can't say I've found many people that have hacked, abused, and stretched the capabilities of the N900 like you have. You are a madman, Estel. ;)

Thank you for the extensive thread full of great information, by the way. It is very appreciated.

Re: Using the N900 as a complete desktop replacement, is it possible?
 

It seems so, as far as my limited (really!) knowledge goes. It is what I got from people that hacked with N900's charging/USB hostmode bits, and practice seems to reinforce that.

Why a moot? BL-5J is so incredibly popular battery, that I don't see it perishing from alternate-manufacturers sources in next ~15 years, if not more. Also, due to lack of "intelligent" battery chip in cell itself, it will be always incredibly easy to modify <any_new_~3.7battery_that_isn't_bigger> to work with N900. Well, as you may be aware, I'm even working on putting 2x 18650 LiIons there ;) I wouldn't be afraid of obsoleting due to lack of batteries.

Also, in case of always-from-AC scenario, it have some benefits, to keep a battery inside (one that you don't care about actual capacity after years of usage). It acts like a integrated UPS ;)

I'm all for new accessories for N900, but I doubt that chinese folks would find it profitable - most people would just stick to have any random battery inside N900, even for always-AC case - for reasons mentioned above.

OTOH, chinese manufactures even produce a N900 motherboards (without any parts, just PCB's), which I can't imagine a market for, either - so, everything is possible ;)

It's because using another X display doesn't "forward" images itself - that wouldn't be possible without some compression (bandwidth), after what you would, basically, get VNC. AIUI, X just sends required data, and device with monitor physically attached to it (RPi, in that case), does all graphic job.

Both :) RPi can route input back to N900, but, if one would like to mess with it, RPi can also route raw USB clients (not only input) back to N900, even in N900-as-client scenario - through USB networking, and one of FOSS USB-over-IP protocols (one similar to THIS). Keep in mind, that I haven't attempted it myself - it's just that there are no technical/logical reasons, why it shouldn't work. I'm just not sure if anyone compiled USB-over-IP clients for N900, so some compiling work would be required (and, as said, to actually have certain device working with N900, you need appropriate modules in N900 kernel- just like when that device is connected to N900 via physical hostmode).

:o Thanks a lot, but I'm just a small firefly here - look at our kernel hacking guys, half of hardware modifications wouldn't be possible without their work.

Well, some people (*wink wink* don_falcone *wink wink*) would just say "get a separate netbook/camera/whatever for that, it will cost the same or less", and they're probably right ;) But. I just like to "stretch" N900 capabilities. After all, it's fully-featured computer (mobile one, but that doesn't mean it should do less), so if it can do some things in practice, why not? Having all those "beautiful things in small package" that we always carry with us (due to having phone functionality), is nice thing.

I used to have "external" digital compact camera - the problems is, that everytime I seen something worth photo'ing, I haven't had it with myself (murphy law), so I ended up doing shot with N900 anyway. After few such situations, I decided that messing with N900 camera is more feasible in practice, and got rid of compact one, focusing on adding camera tripod mount point for N900's mugen cover (which resulted in ugly mod, thatIi'm using up to this date). Thinking about all of fussle it required to put it into mugen cover, I thought "why not to make a whole replacement backcover using better material". And, why not to make whole body, then? That's how replacement body project was born, stretching to it's current layout.

It's pretty much the same with everything else ;)

/Estel

Re: Using the N900 as a complete desktop replacement, is it possible?
 

oh good lord with the walls of text

Re: Using the N900 as a complete desktop replacement, is it possible?
 

in 2009 for e few months my n810 was an only desktop. It did everything.
I used it to make a CV and fin a job, I did tons of emails, I used it to download torrents like video and music and watch (listen) it, of course I used it to serf Internet, blogging, skyping, reading. And as I was in the foreign country I used gps navigation every single day, And it did for me many other things.
I think if n810 could do it, n900 can do it for sure!