[Johan Kanflo] sent us his latest recipe: a blend of one part RFM69 sub-gigahertz radio transceiver with one part ESP8266 module. The resulting dish looks absolutely delicious!
We’re all charmed with the ease of use that the ESP8266 brings to the table — plug it in and you’re talking to your existing WiFi network — but we hate the power consumption for battery-powered applications. WiFi is a power hog. And although ISM-band radio modules make point-to-point communications cheap and power-saving, getting them to talk with your computer takes an adapter.
So [Johan] combined the two radios and made a sweet ISM-radio-to-WiFi bridge. His demo application takes whatever data is sent over the ISM band and pushes it to an MQTT broker on his WiFi network. Hardware and firmware are up on GitHub.
We’ve been wanting a device like this for our home network for a while now. Kudos, [Johan] for making it so easy!
Cutting a field of grass is a straightforward and satisfying process, given a suitably powered mover. A tractor with a rotary topper to hang on its three-point linkage and power-take-off will make short work of the task.
[Donn DIY] had an agricultural quad-bike, but when it came to mowing its lack of a power-take-off meant it wasn’t much use. When he saw a home-made mower for a quad-bike online he had to give it a go himself, and came up with his own take on a mower made from junk.
He started with the rear axle and differential from a Russian built Lada, which he reconditioned, before mounting in a wooden jig with its input shaft pointing upwards. He then made a frame for three mower shafts, onto which he mounted his custom-made rotors and their machined bearing housings. Some pulley machining, and he could then link the rotor shafts to the differential with a series of V-belts and a further shaft to step up the rotor speed.
He wasn’t finished there, after the rotors came a lever mechanism for lifting the cutters off the ground, and a pair of weight baskets to ensure traction was maintained. The result is a mover that takes its drive from its wheels, and cuts grass very effectively when towed behind the quad-bike. The unguarded blades would probably give a farm insurance assessor an apoplexy, but for the purposes of the video below the break at least we can see everything.
3D printers are all the rage, but there’s still space for more traditional CNC machines. For their Hackaday Prize entry, [Andy], [Tim], and [Chris] are building the Sienci Mill – a simple desktop CNC mill that’s able to cut drill and carve everything from wood to circuit boards.
As far as desktop CNC machines go, it doesn’t get much more simple than this. They’re using steel plates for the rails, NEMA 17s for the motors, and a simple stepper motor driver Arduino shield for the controller. The more complex parts are 3D printed, and the BOM doesn’t add up to much.
Right now, the guys are testing their mill on wood, plastic, and aluminum. With 3D printed parts, they’re also able to test a bunch of different spindles from the ubiquitous router to the smaller Dremel. It’s a great project and should be fantastically cheap when the guys finalize the plans, making this a great entry for the Hackaday Prize.
There was a time when you could do what you wanted in your yard and hams could build giant antenna farms. These days, there are usually laws or deed restrictions that stop that from happening. Even if you can build an antenna, you might want to quickly put up something temporary in an emergency.
[Eric’s] solution? Suspend a wire from a weather balloon filled with helium from the local WalMart. The 8 foot balloon took two containers (18 cubic feet) of gas before it would rise sufficiently. Once you have a floating balloon, the rest of the concept is simple: connect a wire (100 feet of 26 gauge), use a tuner to match the load to the transmitter, and you have instant antenna.
We have run out of fruits to name all the single-board computers on the market, but that doesn’t mean you can’t buy a rotten one. Bad documentation, incomplete specifications and deprecated firmwares are just some of the caveats of buying only by price and hardware features. To help you out in case you just need to find a great and open-enough SBC with community support, [Eric] has put together a decent list with 81 individually reviewed boards over at hackerboards.com.
[Jason]’s at it again. This time the LEGO maestro is working on a LEGO BB-8 droid. As a first step he’s made a motorized monowheel that not only races along hallways and through living rooms at the peril of any passing people, but turns as well.
To drive it forward there’s an axle that runs across the center of the wheel and a motor that rotates that axle. He’s also included some weight bricks. Without the mass of those bricks for the rotation to work against, the motor and axle would just spin in place while the friction of the floor keeps the wheel from rotating. If you’ve seen the DIYer’s guide to making BB-8 drive systems, you’ll know that this is classified as an axle drive system.
LEGO monowheel interior shown while leaning to turn
For steering the monowheel left or right he has another mass located just above the axle. Shifting the mass to the left causes the monowheel to lean and move in that direction. Shifting the mass to the right makes the wheel move to the right in the same fashion. Being ever efficient, [Jason] has the motor that shifts the mass doubling as the mass itself.
As with any proof-of-concept, there are still some issues to work out. When turning the wheel left or right it can tip onto its side. Ridges on both sides of the wheel’s circumference reduce the chances of that happening but don’t eliminate it altogether. Also, the steering mass/motor doesn’t yet have a self-centering mechanism; after a turn it’s up to the person holding the remote control to find center. If the mass isn’t correctly centered after a turn, there tends to be some wobble.
As always, we’re looking forward to seeing how [Jason] solves those issues but first he’ll have to put it back together since, as you can see from the video below, it didn’t quite pass the stair test.
We hear a lot about drone surveillance, drone package delivery, drone this, and drone that. Honestly, though, the best use of drones has been taking cool aerial videos and posting them online. Until now.
The US Fish and Wildlife Service plans to cover acres upon acres of prairie-dog habitat with vaccine-laced, peanut-butter coated M&Ms. The snacks also include a dye that will show up in the whiskers of prairie dogs that take the bait, allowing scientists to assess the efficacy of the program. And this is all in the name of saving endangered black-footed ferrets which share burrows with the prairie dogs. It seems they were getting the plague from the prairie dogs.
The quads are outfitted with a “glorified gumball machine” that spreads the vaccine tidbits around. Why a quad? They can cover more space with less disruption to the animals’ habitat. That’s a great application in our book.
