The travel meta-search website Kayak apparently used to have a public API which is no longer available. We can’t say we mourn the loss of the interface we’d never known about. If you are someone who was automating their searches for that perfect vacation getaway deal, there’s still hope. But either way you’ll like this one. [Shubhro Saha] figured out how to access the API used by the Kayak mobile app. We like that he details how to sniff the traffic between an app and the internet and make sense of what is found.
His tool of choice is the Python package Mitmproxy. We haven’t heard of it but we have heard of Wireshark and [Shabhro] makes the case that Mitmproxy is superior for this application. As the name suggests, you set it up on your computer and use that box’s IP as the proxy connection for your phone. After using the app for a bit, there is enough data to start deconstructing what’s going on between the app and remote server which which it communicates. We could have a lot of fun with this, like seeing what info those free apps are sending home, or looking for security flaws in your own creations.
[Thanks Juan via Twitter]
Last July, [Louis] bought a kayak off of Craigslist. It was a pedal-powered device with a hand-operated rudder, and he ended up enjoying his time on the water. [Louis] fishes, though, and it was a bit of a challenge to manage hands free fishing while maintaining a steady course. His solution was an Arduino-powered autopilot that allows him to troll for salmon and Arduino haters with just the push of a button.
In [Louis]’ system, a motor is attached to the steering lever along with a few limit switches. This motor is powered by an Arduino controlled with an LSM303 compass module from Sparkfun.
When the autopilot module is started up, it first checks to see if the compass module is enabled. If not, the system relies on two tact switches to change the position of the rudder. Enabling the compass requires a short calibration of spinning the kayak around in a circle, but after that the steering is dead on.
There are a few things [Louis] would like to add such as a heading display and a bluetooth module for remote control. This setup already landed him a 13 lb salmon, so we’re going to say it’s good enough to catch some dinner.
This kayak to sailboat conversion is well done and makes for an interesting project. But even if you’re not going to be hitting the water on one of your own, the construction techniques are a useful resource to keep in mind. Many of the alterations were done with a plastic welding iron.
[RLZerr] shows off the materials that went into the build right at the beginning of the video which you’ll find after the break. His kayak is made of High Density Polyethylene and he uses other HDPE scraps, PCV parts, and even some aluminum to make everything. To weld HDPE together he uses a plastic welding iron that is like a cross between a soldering iron and a hot glue gun. It has a pad tip that gets hot enough to melt the plastic, but also includes a channel through which additional HDPE filament can be fed to bulk up the connections.
Additions to the kayak include a centerboard, rudder, and mast. The sail is a plastic tarp attached to the PVC mast which has been stiffened with a wooden shovel handle in its core. The rudder and centerboard are aluminum attached to PVC pipes using JB weld. The boat catches the wind easily, but without outriggers [RLZerr] must be careful not to let a big gust swamp him.
Continue reading “Kayak to sailboat conversion shows how to weld plastics”
How can your love of hobby electronics and your participation in the Canadian National Kayaking Team be combined? Why not use your technical know-how to provide a performance edge? [Geoff Clarke] decided to rig up a paddle for data capture to see if they could learn anything.
Here you can see that a series of flex sensors were applied to one of the business ends of the paddle. These are connected to a microcontroller which is constantly monitoring them and dumping the data onto an SD card. The design will provide about nine minutes of data before the storage is used up. That sounds like a number that might need improving. We could see this being useful to log a series of practice runs on the same course, but with different athletes. By graphing and comparing the data, you should be able to make observations about how the paddle is being held and when force is applied that could help the rest of the team improve.
But we’re way ahead of ourselves. The rig was given a premature test-run and the flex sensors were destroyed by the salt water. We wish this had worked out and hope that [Geoff] will give it another try after rethinking the water proofing.
When [Andrea] was looking for a freestyle kayak, he bought the cheap version of a high-end kayak. The hull is exactly the same as the high-end model, but to differentiate between product lines, Pyranha chose to use less expensive fittings. [Andrea] decided to bring his new kayak up to spec (Italian, here’s a Google translation) by fixing the problems in the cheaper model by bringing it up to more professional standards.
When [Andrea] got a hold of his kayak, the back rest was held on by a piece of nylon webbing secured with a plastic clamp. This was bound to fail after just a few outings, so he fixed this with a few steel nuts and bolts. The eyelets used to tie ropes to the kayak were terrible, so with a little bit of nylon webbing and a pair of buckles these were replaced.
Now, [Andrea] has a very nice kayak indeed, for less than the price of the more expensive version. Good job, [Andrea].
We do a lot of useless hacks just for the fun of it so when we see something with purpose it’s pretty exciting. This hack turns any kayak into a motorized vessel that can be controlled by a quadriplegic person using a sip & puff interface. After the break you can see some clips of navigation and an explanation of the hardware.
[Mark’s] system starts by adding outriggers to a kayak to prevent the possibility of the boat rolling over in the water. Each pontoon has an electric trolling motor attached to it that is controlled by an Arduino via a motor driver.
The Arduino takes navigational commands from a sip & puff controller. A straw in the operator’s mouth allows them to sip or puff for a split second to turn left or right. Longer sips or puffs control forward and reverse incrementally, up to a top speed of about 3.7 miles per hour. [Mark] incorporated an auxiliary remote control interface so that a safety observer can take control of navigation if necessary.
His build came in around $1300, a tiny cost if this makes kayaking available to several people each summer. Great job [Mark]! Continue reading “A day at the lake for the disabled”