The Deliverator – Wannabee

So open minded, my thoughts fell out…

Archive for February, 2007

My Computer and My Tinfoil Hat

Posted by Deliverator on 27th February 2007

No, its not what you think.

Tin Foil Hat

I had a busy day today, as I am trying to finish up a recent avalanche of work from clients before I head off to Portland this Thursday to take members of the TRC to the Pacific Northwest FIRST Robotics Competition, but took five minutes to glance through Craigslist to see if there was anything I absolutely needed (so sue me, I am a gadget freak). I spotted an interesting item offered free by a kind gentlemen named Tom Humphreys, a SmartNAV 3 EG from NaturalPoint.

Smart Nav 3

This neat little doohickey allows for hands free control of a mouse cursor. I have one friend with CP who has motor coordination issues which make using a conventional mouse difficult. The International School is also unfortunately amongst many schools in America to see former students return home from Iraq with serious injuries. I know of at least one student who has been left substantially paralyzed from the neck down. I figured one of the two were likely to make good use of the device, so in a break between jobs, I went over and picked it up. I brought it home this evening and have been experimenting with it.

The unit consists of an emitter/sensor device which sits on top of your monitor, plugs into a USB port and accepts click input from foot pedals (what this unit came from) or a variety of other simple switches. Newer versions of the software which comes with the device support voice clicking as well. The emitter/sensor device seems to be a combination of a CCD camera and a few near IR LED emitters. You are supposed to stick an adhesive dot to your forehead, glasses, boom microphone, etc to reflect the IR back at the sensor. Unfortunately, I didn’t have any of the special dots (made by 3m out of the stuff I am sure is used for jogging reflectors), but still wanted to experiment. I found that coins, watch batteries and other similarly reflective round objects made a poor substitute for the real thing. I tried a jogging reflector and found the camera tracked it much better using the test application, but was too unwieldy for actual use. I noticed that NaturalPoint sells a special baseball cap with a reflector mounted on the brim in their accessories section on their website.

SmartNAV3 Reflector Hat

The idea is with the reflector on the brim being farther in front of the point of rotation (your neck), the reflector describes a greater arc due to small neck movements than a reflector mounted on your forehead, making it even easier to track. I decided to imitate this simple solution by taping a rectangle of tinfoil to the front of my FIRST cap. I found a rectangle of foil about an inch tall by two inches wide worked best. Afterwards, my tinfoil hat and I spent about twenty minutes surfing the web, checking email and doing other routine tasks with relative ease. I am sure an official dot would do even better.

Given that the tracking unit simply relies or reflected light, I figured that an emissive target would be even better. I pulled out a 1 watt Luxeon and taped it and a coin cell to the end of my FIRST cap. The tracking was even better than with my tinfoil cap. Unfortunately, taping an LED to one’s forehead isn’t very practical for real world use. I think I will get some reflective tape from the hardware store and see if I can make a better passive reflector hat. If I can’t come up with a better solution on my own, I guess I will just buy some from NaturalPoint, but the hacker in me wanted to see what I could cobble together. Hopefully one of the two above mentioned individuals will be able to make good use of this neat little device. I may just have to pick one of these up in a few years when my wrists are completely shot (my wrists currently make clicking noises which annoy everyone around me and my hands are pretty useless when I first awake in the morning, but I figure they still have a couple good years of use in them).

Posted in Portable Computing/Gadgets, Tech Stuff, Titan Robotics Club | 1 Comment »

Fun with Fon cures Frustrations

Posted by Deliverator on 24th February 2007

After a day filled with frustrations, I decided what I needed was a good, challenging late night hack session. I’ve had a funky little “La Fonera” wifi router sitting on my shelf for a while, so I decided to see what I could do with it. The “La Fonera” is from a spanish company called Fon, which is trying to build a hotspot network by literally giving away access points. The idea is that if you host a Fon hotspot, you can get on any of the other hotspots in the network for free, but non-members have to pay. I am not sure how that business model is working for them. As Matt is fond of saying, “its not my job to support your *^*&^*& business model.” For a while they were giving away WRT54GL’s, but despite a rather large cash infusion from google, I guess this proved too expensive. So, they rolled their own solution in the form of “La Fonera.” I am getting sick of saying La Fonera, so I will just call it the little white box. The little white box is quite little, and white. The little part makes it an interesting target for hacking, while the white part just makes me want to kill whoever started this particular design craze at Apple. So, lets see what we can do with this little white box, eh?

fonera

Sebastian Gottschall, chief developer of the excellent dd-wrt wireless firmware project, recently started releasing builds of dd-wrt for the little white box. OpenWRT is also a possibility. In fact, the little white box ships with a highly modified and locked down version of OpenWRT. Unlike most devices supported by dd-wrt, getting the firmware on the little white box isn’t as simple as just hitting the upload firmware button in the webmin interface (like you can on a WRT54GL). To start with, the little white box checks for a cryptographic signature on any firmware you try to upload using their web interface, so we have to find another method. The little white box uses an unmodified version of the Redboot bootstap environment, so if you can somehow get access to Redboot, you can use it to upload a new flash image from a TFTP server. There is a serial console with pin headers on the little white box. Unfortunately, it is a TTL type serial port, so you would need to build an adapter to use it. Eric Butler was kind enough to offer me the parts I would need (particularly a MAX232 TTL converter chip), but I was in no mood to wait, so I needed to find another way to get access to Redboot.

For this, it sure would help to have root SSH or telnet access to the little white box. I found a page which described a neat form submission data injection attack, similar to what was first used to open up the WRT54G. Unfortunately, my little white box came with a firmware which validates form submissions for things like escape characters. At this point, I am getting sick of the little white box, so I will now just call it lwb. Fortunately, I was able to downgrade to a firmware revision that doesn’t! Once you are at the lower firmware revision, be careful to keep your lwb from going online, as the lwb auto-updates! Using the above linked method, I was able to get myself root SSH access.

Fonera SSH

I quickly used vi to make the change permanent and keep the box from updating itself behind my back. Once into the lwb, I was able to swap in a different kernel, which can be found with some difficulty at this site. After rebooting with this new kernel and a few steps I don’t understand, you get access to Redboot via telnet on port 9000 on the lwb’s wired port.

Once into Redboot, you need to set up a tftp server and use it to serve up the latest dd-wrt firmware files to the lwb by carefully typing the instructions. If you screw up at this stage or any other stage, you are likely to your little white box into a little white brick. Thankfully, all went well and I now have a Fonera which is free as in source as well as free as in beer.

dd-wrt fonera

Once I’ve had some fun with my Freed Fonera, I will probably flash it back to the original firmware, as Fon’s business model just might catch on if google’s deep pockets allow them to give away a few million more of these things.

Many thanks to all those who did a great job documenting the technical details of getting dd-wrt running on the lwb.

Posted in Linux, Operating Systems, Portable Computing/Gadgets, Tech Stuff, Wireless | No Comments »

Shipped

Posted by Deliverator on 21st February 2007

FRC 2007 - Oceanus

Posted in Titan Robotics Club | No Comments »

Is that a Shub-Niggurath in your pocket?

Posted by Deliverator on 20th February 2007

For quite a while, it has been possible to play Doom on the Nokia 770 and Nokia N800 internet tablets. Recently, it became possible to play Quake 2 on the n800, thanks to a port of Quetoo, a speed optimized Quake 2 engine, to the Maemo platform. The port requires the user to copy the original game files to the external SD card slot manually, after installation of the applcations itself, and then edit a config file to set key-bindings and other options. The game clips along at a decent pace at 800*480, although for smooth frame-rates you are better off sticking to the default 400*240 resolution. I found playing Quake 2 on my n800 using a Nokia SU-8W Bluetooth keyboard to be almost tolerable. Having to drag the stylus across the screen left something to be desired, however. I hope someone gets bluetooth mice working on the n800 pronto! Quetoo on the n800 really demonstrates the power of these amazing little internet tablets. It really is like being able to carry around a full fledged computer in your pocket. Quetoo also demonstrates the benefit of using Linux as a basis for portable devices. To my knowledge, this port was pretty much a straight recompile from the Linux source. I can’t wait for OpenMoko! Now that will be a real smartphone!

Here is a video of Quake 2 running on my n800.

Posted in Gaming, Linux, Portable Computing/Gadgets | 1 Comment »

All Nighter at the JPF and 2007 Pre-Ship Event

Posted by Deliverator on 18th February 2007

The TRC has been working overtime to finish Oceanus in the ever more threatening face of Tuesday’s ship deadline. Friday night, we decided to work through the night at the JPF, with a parallel effort going on at Ian Hovander’s house as they worked to finish the ramps, which Oceanus will hopefully deploy during the match to gain a massive point bonus. Saturday morning, the JPF played host to a pre-ship event, where teams from around the area met to skirmish against other teams. Too tired for any more words, here are some pictures, instead.

Posted in Titan Robotics Club | No Comments »

Very Tired

Posted by Deliverator on 10th February 2007

… but satisfied

-110 feet of wooden field railing
-54 feet of 6.5″ high end zone stations
-2 additional target lights put up
-Oceanus (Codename: Lollipop) driven for the first time.
-3 years of TRC robots running around the field.
-Helping rookie team Tahoma (the other TRC) with their first robot

Good times. Going back for more tomorrow…

The Gallery

Posted in Titan Robotics Club | No Comments »

Dean Kamen Speaking in Seattle

Posted by Deliverator on 8th February 2007

Dean Kamen

Dean Kamen, perhaps best known for his invention of the Segway (and perhaps more significantly for the first insulin pump and an improved dialysis machine), is coming to Seattle this Friday to speak about one of his less well known projects, developing simple devices (targeted for use in the third world) that generate electricity and clean water and operate off thermal differentials. Dean is also one of the cofounders of FIRST, the organization in which the Titan Robotics Club participates. He will be speaking at 7:30 at Town Hall Seattle located at 8th and Seneca. Tickets are available at the door only and are $5.

Posted in Titan Robotics Club | No Comments »

Explosive Growth in N800 Development

Posted by Deliverator on 7th February 2007

Since the recent release of the N800, Maemo related development has really taken off. Nokia has really helped foster this development with the sourceforge-like development site Maemo.org, well documented SDK´s and even a preconfigured dev environment released as a VMWare virtual computer image. They have also given away some 500 N800´s to select OSS developers. Whatever the reason, the dev community seems to be growing by leaps and bounds. Here are a few tidbits of dev news:

-Quake 2 has been demonstrated running on the N800 at quite acceptable frame rates. This really demonstrates the drastic improvement the more modern 330mhz Omap chip in the N800 offers over the older OMAP chip in the N770.

-Dual boot from a SD/MMC card is now available for the N800. This really makes it possible for developers to muck about with the OS internals without worring about needing to reflash or possibly brick their device.

-Probably as a direct result of the previous news item, some people are fooling around with full blown windows managers and producing windows manager switching scripts. The Hildon UI is well adapted to the constraints of a mobile tablet, but it also requires existing applications to be tweaked to work properly. Having a full window manager available to run unmodified applications will allow the use of a much wider range of OSS without anything more complicated than a recompile.

-Developers discovered that the N800 contains two previously undocumented chips on the motherboard, hidden under metal RF shielding. The first is an FM radio tuner. A desktop applet to control the FM radio was released by Nokia shortly after the discovery. The radio works quite well, using the headphones as an antenna. The applet has the ability to switch the sound between the internal stereo speakers and headphones when using the headphones as an antenna. With the new alarm framework, this should make it easy for a FM radio alarm clock to be developed.

The other chip discovered in the N800 is a USBOTG power controller. While currently unsupported, many people hope that this will allow for powered hostmode for external devices. Currently, plugging in things like USB keyboards requires the use of a powered USB hub or the construction of a USB power injector.

-Nokia released an updated version of their Mediastreamer application, which supports streaming of various forms of content such as pictures and music from uPnP enabled media servers. The new version adds support for video as well.

-There are now instructions available to get Mono, a OSS implementation of the .NET Framework, running on the N800 and N770. There are still no MAEMO specific bindings in MONO yet, but this is a good step towards having applications that can run on the desktop and on the Nokia Internet Tablets without recompilation.

Posted in Linux, Mobile Blogging, Operating Systems, Portable Computing/Gadgets, Tech Stuff | No Comments »

3 Days at JPF

Posted by Deliverator on 5th February 2007

Spent the past 3 days at the Joint Practice Field. Friday, the TRC and Eastlake Robotics showed up and got the carpet in place, taped sections together and marked out all the field dimensions for this year’s FRC game. We then got the rack in place and did some driver/human player training.


Moving

After getting the field set up, Eastlake split their time between doing vision system coding and playing Halo on an Xbox, which they somehow managed to smuggle into the JPF in their shipping crate :)


Eastlake Playing Halo

Saturday, the TRC’s drive team headed to the JPF and drove Gaea, last years FRC robot, around the field for a good chunk of the day. I felt like this was time very well spent, as we got a good sense of upper limits for what is achievable during an all too short match period. I think Jonathan, this year’s drive train operator is going to be a great driver. He exhibits a great deal of poise and control on the field and has excellent spatial perception. We ran a number of exercises where he had to run the robot across the field at high speed, avoiding obstacles and then wind up carefully aligned to the rack (simulating scoring against opponents) and he nailed it more often than not on the first try. He also did a great job of getting up a simulated ramp.

Hopefully, we will have an actual ramp to train with shortly. Ian Hovander’s father Burt has been working hard to finalize a prototype ramp for this year’s competition. Burt managed to create a ramp that is very light (~18 pound estimated) but sturdy enough to endour several weeks of slamming by 120 pound robots. As light as he has made then, we are likely going to go over the weight limit if we choose to mount two of them on the robot. Hopefully we will be able to shave off enough weight in other places to enable us to mount two ramps.


Ethereal Ramp

On Sunday, Joel, Paul and I headed to the JPF to work on autonomous coding. Paul and Joel worked on merging some vision system object tracking code provided by Kevin Watson with our codebase. They ran into some difficulties due to different ways of handling serial ports, but I think they have most of the kinks worked out now. Hopefully we will have enough time to use the camera for something productive in this year’s competition. I spent most of the day putzing around cleaning up the JPF, putting up a target light and numbering the goals with a sharpie. Exciting, eh?

Target Light

Here is a link to pics from the JPF from the last 3 days.

Posted in General, Titan Robotics Club | No Comments »