Garmin GPS
The Garmin eTrex Summit GPS arrived today. Been playing with it lots so far, and it seems very spiffy. Need to write some Python code to take data out of it though, and convert it to a useable format.
Add comment April 12th, 2005
Archive for April, 2005
Trango
Downloaded and read the PDF manuals for Trango Link-10 and Atlas point-to-point wireless systems today. The main glaring problem is that they need to be set up in a master/slave relationship, with the master programmed with the slave’s MAC address. The slave doesn’t broadcast it’s MAC address, so it has to be entered manually into the master before a link can be established. This poses problems for a rapid-deploy setup, as we don’t know what other nodes are out there, let alone the MAC addresses of possible slave devices. What we really really need is a bootstrapping system, much like what Ian is working on, with low-bandwidth CB radio links to do the initial broadcast of available interfaces, so that the nodes can enter information into the Trango master unit before establishing a connection. An extenstion to this would be to have each node broadcasting it’s location, available interfaces, and possibly other information, so that another node can pick this up, and align it’s antenna accordingly.
For now though we’ll have to settle with manually setting up MAC addresses for Trango links, as the low-bandwidth bootstrapping isn’t going to occur any time soon.
Add comment April 11th, 2005
No mesh for Minginui?
While SOWN is pretty cool, it’s looking increasingly like the Minginui network is going to have to be deployed manually, instead of as a mesh. There are just too many things getting in the way (mainly trees) to have a nice mesh setup. Looks like we’ll have one house connected to the sector antenna on the hill (must find out the name of that site) running in master mode and a few of the closer houses hanging off that as clients. Then we’ll beam over to the other side of the town with some high-gain directionals. I think a manual set up is going to be far better, given the odd layout of the town and the fact that the network is probably going to be pretty sparse. It’s also going to save a few dollars in the long run, as we can customise each node. Not all is lost though, I’ll probably use my new found knowledge of WDS (thanks to SOWN) with the mini-network I’m going to have to deploy for a PhD student later this semester.
Add comment April 8th, 2005
More accurate compass results
Been pretty slack the last couple of weeks. Could make excuses, but I won’t. Re did the compass experiment to see if I could get better looking results by moving the compass away from potential sources of electromagnetic interference, such as the computer, power supply, etc. In doing this I made the method a bit more robust, as I was able to secure the big sheet of cardboard down better, thus making the experiment more accurate again. Ran into problems with the Dick Smith multimeter constantly adding about 0.02v each time round the experiment. I think this must be due to it “warming up” as by the third time round the results were consistent. Results look much better - now to interpret them. Finding a general formula is going to be extremely tricky, I think. Will post results at some point in the future.
Add comment April 8th, 2005