offtopic

2008-05-14

Could we all agree to modify our blog feed URLs so that only internet-tablet-related things end up on planet maemo? Competing hardware and software is okay, even, but some of the stuff that’s been on here lately is completely off topic.

When I wanted to be part of planet maemo, I setup a separate blog just for internet tablet related stuff. I realize that’s not possible for everyone, so I suggest this:

With wordpress (which I use), to narrow down the rss entries to a related category, don’t just copy and paste the regular url-for-my-blog/feed link at the bottom, but use url-for-my-blog/category/internettablet/feed/ for the url. The only difference is the category/internettablet/ part before the feed/ and you have to make it a category that you’ve been using on your blog. If you have more than one category, you could setup a yahoo pipe that concatenates all related entries and then make that what gets posted to planet maemo.

It would be much appreciated by almost everyone hooked into this feed.

Thank you for reading this nearly offtopic post.

bluetooth gps receiver woes

2007-02-16

I think maemo mapper is the killer app for the internet tablet. I use my 770 for lots of other things, but having a quick, zoomable copy of a street map and satellite map of where I live and drive and bike and hike on a handheld with this nice a screen is great. I downloaded all the maps for the island I live on from google maps. Even got a temporary ban from them after about 300 MiB (lots of .jpg files that were really html files saying “service unavailable at this time” or somesuch; had to write a script to delete the ones that weren’t images and wait about a week to download more). Since the new version of mapper, I’ve downloaded all the maps from virtual earth, too (street, satellite and hybrid). Now you might say that all this is somewhat silly, since the island isn’t that big and I rarely travel to the other (unknown) side of it, but I still like seeing what it all looks like from above.

After a few months, I got a bluetooth gps receiver as a present from my dad (it was a present because I’m poor due to the expensive island I live on) and it’s an excellent addition to the setup. Now it’s a quick, zoomable map centered here, wherever here happens to be.

Anyway, I was trying to figure out why maemo mapper wouldn’t connect properly to the gps the first time I tell mapper to connect to it after every time I power cycle the gps (bluetooth connection was okay, but it would never even parse the nmea sentences). Not really a terrible problem – all I had to do was uncheck and then recheck “enable gps” in the menu, but less than ideal. I asked around and found some help on internet tablet talk. Someone there suggested that it was in “sirf” mode instead of “nmea” mode when it came on initially. I checked it out some and found a utility to change a sirf gps receiver between sirf and nmea modes. It was a series of perl scripts and there was a hardcoded directory that had the developer’s home dir in it. I fixed that and then ran the script. This is where the tale turns sad. I still don’t know exactly what the script did, but from then on, it would output the initial “this is a sirf star gps receiver running on such and such a frequency and at such-and-such a baud rate etc” and then about 3 or 4 blocks of nmea sentences and then just nothing or gibberish as if it had changed baud rate after that. I tried forcing the serial port on my computer into every baud rate I could remember back from the days of modems and 8n1 hoobajooba and it was always gibberish after about 50 lines of normal stuff.

That was about a month ago, so I’ve been without bluetooth gps since then. The gps part still seemed to work, I assumed because after being on for a couple minutes, the “I’ve gotten a gps fix light” was blinking as if it had found one.

Tonight, I decided to find out what the hell was wrong. I cracked that bitch open, got out the oscilloscope and found where the sirf ic was talking nmea sentences to the bluetooth ic. I found it. It’s pin 14 if you care. Feeling clever, I soldered a wire to it on a DB9 cable and plugged it in thinking I could at least tell that way if the gps receiver was generating nmea sentences correctly and getting a fix. cat’ing /dev/ttyS0 gave me nothing and after a quick look on the scope, I remembered the difference between rs232 and rs232c. The two ics were talking at 3.3V or 5V, but not at 12V (or was it +-12V? – I forget). Anyway, short of a transistor and a 12V power supply or a MAX233, this wasn’t gonna work.

I gave up on that idea, and decided I should do what I wanted to try a month ago when it first broke and I first opened it up. There’s a small watch battery inside that’s soldered into place to keep some data on the current gps info so it can do a warm start instead of a cold start. At least that’s what I assume it does. I unsoldered one battery lead, shorting the battery out a few times in the process because the wires are about a millimeter apart. Let it sit for a minute or so and soldered it back in. Turned the thing on, cat’ed /dev/ttyS0 and voila, nmea sentences that kept going. I put it back in its case and brought it and my 770 outside to get some satellite goodness and it got a gps fix. Took longer than usual to get a fix, corroborating the cold start / warm start theory. Hooray, problem solved. Lesson: If you fuck up your bluetooth gps receiver, just unsolder/resolder the little battery inside and you have another chance to play with it for a while before trying another random perl script you downloaded from the internets to fuck it up again. :) I tried searching google for many hours trying to find the information contained in that last sentence, so hopefully google will find this page soon and some other idiots who mess with their new toys won’t be without their toys for as long as I was. Happy soldering.

customizing what gets backed up on the internet tablets (workaround for bug #974)

2007-02-01

A few days ago, I submitted a bug because os2006 doesn’t backup/restore my /etc/apt/sources.list (the list of application repositories I typed in). Paul Klapperich suggested the custom backup trick to add your own files and dirs to what gets backed up and restored. According to Jakub Pavelek (of nokia), /etc/apt/sources.list is backed up on os2007 on the n800, but this info still might help somebody if there’s anything else they want backed up.

I created a file called my-custom-backup.conf based on this and I think others might appreciate having it, since it fixes 2 bugs or adds 2 features (depending on how you look at it) to os2006 – it backs up the application repository list and all archived email (among other things – see below).

It saves the following files/dirs for the following reasons:

/etc/apt/sources.list list of the application repositories
/media/mmc1/.archive this is where the email program stores “archived” emails – I lost a bunch of these when I reformatted my rsmmc card to have 512 byte blocks for maemo mapper a while back because I didn’t check for hidden files on the card
/etc/others-menu applications.menu is already saved in the default backup configuration, but I thought I should save this, too
/etc/hosts I manually enter the ip addresses of my other computers in here so I can scp from the 770 with a machine name instead of an ip address
/home/user/.ssh this is so I don’t have to share my keys across my machines after every os update on my internet tablet, and also so I can have my usual login name on my other machines in .ssh/config – the default for ssh is to use the current username, which is “user” on the 770
/home/user/.bash_profile I got used to the alias ll=”ls -l” on redhat a few years back and can’t get by without it
/home/user/.bash_history
/home/user/.ash_history
/home/user/bin for a couple scripts I wrote
/home/user/keys the ssh keys for the other machines
/media/mmc1/.albums this is for obscura, which is already looking really good
/home/user/.thumbnails I think this is where file manager stores the image thumbnails – might as well back it up
/etc/…/my-custom-backup.conf this config file, of course

Instructions:
download my-custom-backup.conf, edit it to suit your needs, get root & xterm on your 770, and as root, copy my-custom-backup.conf to /etc/osso-backup/applications/ and backup to your heart’s delight. I tested restoring with this custom backup file and it didnt’ brick my device, which I look at as a success. :)

A couple notes:
It silently ignores files & dirs that don’t exist.
You can’t make up your own categories, at least not by just mentioning it in this .conf file. I tried this with the category name “shmoopy” and it was silently ignored.

Bugs: Some of the stuff doesn’t really belong in the settings category. I had it put .archive in the email category and .albums and .thumbnails in the media category, but everything else ends up in settings.zip. The file is easy to edit – as I said, edit it to suit your taste.

Anybody that has more ideas on what to backup that’s not in the default nokia-provided (or some application-provided) setup, leave a comment here.

updated 2007-02-01 9:33pm HST: added /etc/osso-backup/applications/my-custom-backup.conf

videoconferencing / video chat

2007-01-12

Any word on whether you can videoconference from an n800 to anything besides another n800 right now? (I only have a 770, so I can’t test).

Undoubtedly (I like positive thinking) the skype client will take advantage of the webcam api to provide video connectivity to skype users on win/mac (since the regular linux client doesn’t do video AFAIK). It’ll be a good thing, because my parents use skype on windows and my girlfriend uses skype on her mac. So they’ll finally be able to see me. Not that they have webcams, mind you. But once it does work, I’ll have an excuse to get each of them a webcam.

Use the Nokia 770 as a bluetooth keyboard for the Nokia N800

2007-01-06

Looks like the successor to the Nokia 770 internet tablet is about to come out, called the Nokia N800. Here’s the unofficial announcement from several places:

So here’s my idea: since there’s a program that makes either one into a bluetooth keyboard, I’m planning on getting a N800 and using my current 770 as its keyboard. Damn, that’s probably the most expensive bluetooth keyboard there is out there (even more expensive than this one).

2007-01-07 10am: Update: added one more link to pictures
2007-01-07 11:15am: Update: added several more links and rearranged links


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