PJON, pronounced like the iridescent sky rats found in every city, is a cool one wire protocol designed by [gioblu].
[gioblu] wasn’t impressed with the complications of I2C. He thought one-wire was too proprietary, too complicated, and its Arduino implementations did not impress. What he really wanted was a protocol that could deal with a ton of noise and a weak signal in his home automation project with the smallest amount of wiring possible.
That’s where is his, “Padded Jittering Operative Network,” comes in. It can support up to 255 Arduinos on one bus and its error handling is apparently good enough that you can hold an Arudino in one hand and see the signals transmitted through your body on the other. The fact that a ground and a signal wire is all you need to run a bus supporting 255 devices and they’ll play nice is pretty cool, even if the bandwidth isn’t the most extreme.
Aside from the cool of DIY protocols. We really enjoyed reading the wiki describing it. Some of the proposed uses was running your home automation through your ducting or water pipes (which should be possible if you’re really good at isolating your grounds). Either way, the protocol is neat and looks fun to use. Or check out PJON_ASK if you want to do away with that pesky single wire.
These brave birds are weapons of war. Well, not these actual birds… they’re just models used for this photograph courtesy of a taxidermist. But their living relatives were used to take spy photographs during World War I. [Dr. Julius Neurbronner] didn’t suddenly jump into the field of avian photography. He, like his father before him, used homing pigeons to deliver prescription drugs in loads of up to 75 grams. This makes us wonder if the birds are ever used in modern drug running?
The inspiration came when the doctor found out about subminiature cameras available at the turn of the twentieth century. Those cameras included a tiny roll of film, allowing for several images to be taken. He figured out a way to make a timer that used a pneumatic system to trigger the shutter in the camera. You can see a diagram of the timer mechanism here. The idea is that the birds will always be able to find their way home. So if you take them to a starting point that puts the enemy lines in between them and home base, they’ll fly over and get some juicy recon in the process.
That’s pretty old school. But we’re still tying things onto birds these days. Here’s some modern tech that uses sun-up/sun-down to track travel habits.
[Thanks F via The Atlantic]
Yes, you read that correctly: electronic mail carried by birds. [Ferdinand] tipped us off to this story, which involves combining new and old methods in transferring data. The Unlimited Group, a firm in a remote section of South Africa, transfers loads of encrypted documents to a second office 50 miles away. A pricey broadband connection would take between 6 hours and two days to transfer a standard load (4GB) of data between these locations. On the other hand, Winston (seen above) can complete an equivalent flight within 45 minutes. A memory card is strapped to his leg, and using his wit and instinct, Winston finds his way home. For those without their calculators on hand, Winston’s bandwidth is between 7x and 63x faster than what they had before. If his flash card were to be upgraded to 16GB, that would be an instant fourfold increase on top of current gains. As [Mark] pointed out on the Daily Mail website, homing pigeons still need to be taken back to their departure point.
This solution still has its advantages over a courier: they are lower in cost, they work over longer hours, and have potentially faster delivery speeds. Multiple pigeons can be transported back at once, and released with data as needed.
There is no doubt that [Johnny Lee] is the authority on Wiimote based projects. So, when he compiles a list of his favorite Wiimote projects, we definitely pay attention. He’s organized the list as a progression of the unusual. By the time you get to ‘Chicken Head Tracking‘ at the bottom, you’ll be adequately prepared. You’re bound to get some inspiration from the list even it’s building a pigeon guided missile.