New semester

Well, I am about to start school again. I got a lot done over the summer though. Check bit.ly/barbierover for some updates on the rover project. I also got my server up and running. I installed wordpress (which isn't quite working yet) and drupal going as well. Drupal can do blogs though, so I might just use that. My server is running Windows Server 2008 database edition. I set up remote desktop and I installed loginexpress. The physical machine is sitting under my desk at home. I will have my brother turn it on and then I can remotely connect and add/remove roles and stuff. I am not completely happy with it yet, so I won't release the URL yet. I won't have a lot of time to work on it during the year, but I will work on it when I can.
My buddy Bandit5317 over at xbox-scene.com just made engadget with his micro xbox. He is also working on an xbox360 laptop. That dude is quite a craftsman.

meh

Haven't posted in a while because of work and the rover project. I am still working on my new server as well. I have a lot of projects going and they are all sort of coming together, since I want to host the rover control on my website. Anyway, keep following the rover blog and I'll put some other updates here when I have time.

Barbie Rover site up

Here it is: the project website for the rover.

http://www.prism.gatech.edu/~hscott7/rover

It has its own blog as well. Still working on it, but most of the updates will now go on that blog, not this one.

How to make an ad-hoc network between Windows and Linux

How to set up an ad-hoc network between Windows and Linux:

1. Disconnect both computers from any networks
2. make sure you have wicd installed on the linux laptop
3. On windows, go to control panel->network connections
4. right click on your wireless interface
5. go to properities and on the networking tab, scroll down
to Internet Protocol Version 4 (TCPIP/IPv4) and click on it once
6. Click properities
7. click use the following IP address and enter the following:
IP address: 192.168.1.2
subnet mask: 255.255.255.0
default gateway: 192.168.1.1
and leave the other boxes blank. Click Ok.
8. Windows may yell at you, just click ok or continue.
9. On linux, open wicd and click network->create ad-hoc network
10. name the network whatever you want (the ESSID)
11. Give it the IP 192.168.1.1
12. Click ok.
13. Connect to the new network with windows
14. You're done!

Coming soon

I just finished a website documenting the barbie car project. Once we get a video of the test run, I will post a link and go live. I will also announce the project on several websites and see if I can get on hackaday.

Random note:

Heron's fountains work underwater. The pressure from the water pushes down the air in the bottles. I could feel the water flow underwater and want to try it again with colored water in the bottles.

another update on the car

We are really only waiting on 1 part to come in the mail, our other motor controller.
Once we have that, it will take about 30 seconds to install it and get the remote control going. I was having a problem
the other day with my ubuntu laptop. After trying to install some stuff to get skype to work, I rebooted and my wifi
stopped working. I did everything I could think of and finally found a forum post that helped. It turned out that by
going to system->administration->hardware drivers, I had to enable the wifi driver. Once I did, it worked great. I rebooted
again and had the same problem, but this time the driver was enabled. I disabled it and it worked. I am now working on
getting the cameras to work. I am using ZoneMinder for linux. Its designed to be used as a home security thing, and
it can support multiple cameras. But most importantly, it can be accessed from the web and can record. It can even detect
motion and only record then, which is cool. So the way we are setting this up, we should need only a browser to control
then entire car. Just connect with hamachi and then access the page with controls and the monitor page. I also managed
to get a spare linksys wrt54g router going on only batteries. This will be how we control the car if there is no
wifi. Just fire up the router and connect to it and control it on a local network. I have been wanting to get some
relays for the arduino so i can turn stuff on and off like the router. I also got a bit more hardware done, including the
charging port. I noticed that on the back of the car was a little fake nozzle for gas. So I found a male and female
12v cigarette lighter connecter and installed it. Its pretty awesome, now you just open the little gas thing
and plug in the charger. I found a nice piece of pvc that I can use to make the rocket launcher. I plan on using
vex to build a holder for it and a gear assembly. Then we can pick what angle to launch the rocket from and put it at
0 degrees for storage. We might even be able to get a sensor on there that tells you what angle you are at or at least
when you have hit a certain angle. I also came up with a design to mount the camera with. Basically its just a
long piece of pvc with the camera at the top. Then just underneath it is the usb hub with the bluetooth and wifi dongles.
If I can find a pigtail, then I can also put the antennas from the linksys router up there for better connection.
That whole thing rotates. In the end, we will have 2 cameras. The first is the logitech that is for the main driver.
The second is the built in camera on the latop that will be looking at a multimeter monitoring battery and anything
else we want. I also still need to get some sort of tread for the tires. This thing is really close to done now.
We are planning on debuting it at bandcamp during a night practice. In which case it will need lights...

another car update

I know I haven't given a big update yet, so here it goes. The car is painted and we have 1 wheel and axel mounted. We solved the problem with the motor controller we were having: it turns out that the one we were using was broken when we got it. Once we started using the other one we order, the code worked great. The lights responded and the voltage went from -12 to 0 to 12. I emailed the company who made them and I found out that the PWM range is not standard for them. The PWM is Pulse Width Modulation, which is how servos get talked to. Instead of sending a static voltage, it sends pulses. The length and width of those pulses decide how the servo acts. So for us, pulses of length 1ms mean that the servo is going in full reverse (0 degrees on an r/c controller). 1.5ms is neutral (90 degrees) and 2.0ms is full forward (180 degrees). The duty cycle doesn't matter that much, but should be around 20ms. On the controller that we got, its cool because if you don't supply an extrernal battery, it executes the code using the 5v it needs to run (so you can get -5v to 5v). Anyway, so we got all excited and the multimeter was reading correctly, so we plugged in the motor and barely got any movement at all. We tried different size motors and they all worked ok. We concluded that it was drawing too much current. The controllers we got could handle 3 amps continuous and 9 amps max, at which point it cuts the power to save itself. It does the same for temperature. I noticed that even after only a few seconds, it started getting really hot. Based on everything that we had seen, we concluded that we were drawing too much. We calculated a theoretical draw of 13 amps (i fried the current measuring part of my multimeter). Our solution was a giant resistor. We did some math and decided that we would do 3- 1 ohm 30 watt resistors in parallel straight off the battery. We ordered those parts yesterday and they ship today. I am also going to try to get another motor controller in the mail to replace the broken one. If all goes to plan, then we should have it working maybe by the end of the week. I have to finish up some code for the arduino and the web interface. Right now the demo page for the web interface is just php buttons. I wanted to support keyboard use to make it easier, and it looks like a bit of javascript should do the trick. I will have the mouse be in a special box that reads the keystrokes. When a key is pressed, its ID is sent as a variable to another php page that isn't loaded. That way we should be able to have php do stuff without reloading the page each time. I am still experimenting with that, but the demo works for now. Then the only thing we have to do is install everything and get the extra stuff working. The extra stuff are things like rockets, speakers, lights, etc. We plan on debuting the car at bandcamp this year. Imagine this: its night, and they are almost done with practise. Then out of now where, a little power wheels are comes driving accross the field playing music with lights. It drives the the side of the feild and launches a rocket. It is this image that keeps us working. We are still trying to think of other things to attach to the car. I thought about some sort of turbo feature. Maybe use a relay on one of the arduino output pins to trigger a dump of like an extra 6-12 volts. We also will have a pan/tilt for the webcam. The webcam will be able to see my multimeter screen, so we can keep an eye on the battery, because it can't get below 10.5v. On that note, it turns out that you can charge a battery with a charger rated at the same voltage, but lower amp-hour rating. It just takes longer. The other thing we want to do it have an airsoft gun with pan/tilt as well on the back.