Explore Low-Energy Bluetooth by Gaming

For several years now, a more energy-efficient version of Bluetooth has been available for use in certain wireless applications, although it hasn’t always been straightforward to use. Luckily now there’s a development platform for Bluetooth Low Energy (BLE) from Texas Instruments that makes using this protocol much easier, as [Markel] demonstrates with a homebrew video game controller.

The core of the project is of course the TI Launchpad with the BLE package, which uses a 32-bit ARM microcontroller running at 48 MHz. For this project, [Markel] also uses an Educational BoosterPack MKII, another TI device which resembles an NES controller. To get everything set up, though, he does have to do some hardware modifications to get everything to work properly but in the end he has a functioning wireless video game controller that can run for an incredibly long time on just four AA batteries.

If you’re building a retro gaming console, this isn’t too bad a product to get your system off the ground using modern technology disguised as an 8-bit-era controller. If you need some inspiration beyond the design of the controller, though, we have lots of examples to explore.

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Vintage Headphones Bluetooth Conversion Goes The Extra Mile

[KaZjjW] wanted to retrofit a pair of nicely styled vintage headphones to be able to play wirelessly over Bluetooth. In principle this is an easy task: simply stick a Bluetooth audio receiver on the line-in, add a battery, and you’re all set. However, [KaZjjW] wanted to keep the aesthetic changes to the headphones at an absolute minimum, retaining the existing casing and volume control, whilst cramming the electronics entirely inside and out of sight.

With the inherent space constraints inside the cups of the headphones, this proved to be quite a challenge. The existing volume potentiometer which hung half outside the case was remounted on an ingenious hinge made of two PCBs, with the pot floating next to a surface mounted switch. This allowed it to not only control the volume, but also act as an on/off switch for the Bluetooth. The only other existing cuts in the casing were a circular hole for the audio cable, and a slit for the cable strain relief. These worked perfectly for an LED status indicator and micro-USB battery charging.

The main chip used for receiving audio over Bluetooth was the BM62 by Microchip. It’s a great all-in-one solution for this kind of project as it has built-in battery charging, an on-board DAC and audio amp, as well as a serial control interface. In part 2 of the project log, the process of programming the BM62 was documented, and it was painful – it’s a shame that the software support lets it down. But a hacker will always find a way, and we’ve seen some pretty neat hacks for reprogramming existing chips in off-the-shelf Bluetooth headphones.

Two PCBs for the pot button hinge, one for the LED and micro-USB connector, as well as one for the Bluetooth receiver and a PIC. That’s four PCBs in a pretty small space, enabled by some commendable design effort both electronically and mechanically. It certainly paid off, as the finished product looks very slick.

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Worn Train Rails Get Judged by Laser

[Calango] is a railway technician, and for a school final project created the Rail Wear Surveillance Trolley (RWST) which is a delightfully designed device made mainly from PVC conduit with one job: travel down a segment of train track while shining a green laser onto the rail, and capture camera images. The trolley holds both the laser and the camera at just the right angles for the camera to capture a profile of the rail’s curved surface. The images are sent via Bluetooth to a smartphone for later analysis. Rail wear can be judged by checking how well the profile of the rail conforms to the ideal profile of an unworn segment. The trolley is manually pushed by an operator, but [Calango] says that ideally, it would be self-propelled and able to inspect a length of the track then return on its own.

The project was made on a tight budget, which led to some clever solutions like using a rotary encoder attached to a wheel as a makeshift distance sensor. If things get desperate enough, it’s even possible to roll your own rotary encoder with a 3D printer and two microswitches.

R/C Rocket-Beest Burns Up Fuses Out There Alone

We’re beginning to think the “S” in [Jeremy S Cook] stands for strandbeest. He’ll be the talk of the 4th of July picnic once he brings out his latest build—a weaponized, remote-controlled strandbeest that shoots bottle rockets. There are a bank of money shots up on Imgur.

This ‘beest is the natural next step after his remote-controlled walker, which we featured a month or so ago. Like that one, the locomotion comes from a pair of micro gear motors that are controlled by an Arduino Nano over Bluetooth. The pyrotechnics begin when nitinol wire cleverly strung across two lever nuts is triggered. All the electronics are housed inside a 3D-printed box that [Jeremy] designed to sit in the middle of the legs. We love the face plate he added later in the build, because those gumdrop LED eyes are sweet.

Can you believe that this vehicle of destruction began as a pile of innocent, pasta-colored pieces of kit? We dig the camouflaged battleship paint job, ’cause it really toughens up the whole aesthetic. And really, that’s probably what you want if you’re driving around a spindly beast that can just shoot rockets whenever. Let’s light this candle after the break, shall we?

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An Arduino Powered Tank Built To Pull Planes

Surely our readers are well aware of all the downsides of owning an airplane. Certainly the cost of fuel is a big one. Birds are a problem, probably. That bill from the traveling propeller sharpener is a killer too…right? Alright fine, we admit it, nobody here at Hackaday owns an airplane. But probably neither do most of you; so don’t look so smug, pal.

But if you did own a plane, or at least work at a small airport, you’d know that moving the things around on the ground is kind of a hassle. Smaller planes can be pulled by hand, but once they get up to a certain size you’ll want some kind of vehicle to help out. [Anthony DiPilato] wanted a way to move around a roughly 5,200 pound Cessna 310, and decided that all the commercial options were too expensive. So he built his own Arduino powered tank to muscle the airplane around the tarmac (if site is down try Google cache), and his journey from idea to finished product is absolutely fascinating to see.

So the idea here is pretty simple. A little metal cart equipped with two beefy motors, an Arduino Mega, a pair of motor controllers, and a HC-08 Bluetooth module so you can control it from your phone. How hard could it be, right? Well, it turns out combining all those raw components into a little machine that’s strong enough to tow a full-scale aircraft takes some trial and error.

It took [Anthony] five iterations before he fine tuned the design to the point it was able to successfully drag the Cessna without crippling under the pressure. The early versions featured wheels, but eventually it was decided that a tracked vehicle would be required to get enough grip on the blacktop. Luckily for us, each failed design is shown along with a brief explanation about what went wrong. Admittedly it’s unlikely any of us will be recreating this particular project, but we always love to see when somebody goes through the trouble of explaining what went wrong. When you include that kind of information, somewhere, somehow, you’re saving another maker a bit of time and aggravation.

Hackers absolutely love machines with tank treads. From massive 3D printed designs to vaguely disturbing humanoid robots, there’s perhaps no sweeter form of locomotion in the hacker arsenal.

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Roll A Black Box For Your Wheels

Telemetric devices for vehicles, better known as black boxes, cracked the consumer scene 25 years ago with the premiere of OnStar. These days, you can get one for free from your insurance company if you want to try your luck at the discounts for safe driving game. But what if you wanted a black box just to mess around with that doesn’t share your driving data with the world? Just make one.

[TheForeignMan]’s DIY telematics box was designed to pull reports of the car’s RPM, speed, and throttle depression angle through the ODBII port. An ODBII-to-Bluetooth module sends the data to an Arduino Mega and logs it on an SD card along with latitude and longitude from a NEO-6M GPS module. Everything is powered by the car’s battery through a cigarette lighter-USB adapter.

He’s got everything tightly wrapped up inside a 3D printed box, which makes it pretty hard to retrieve the SD card. In the future, he’d like to send the data to a server instead to avoid accidentally dislodging a jumper wire.

If this one isn’t DIY enough for you to emulate, start by building your own CAN bus reader.

3D Printed Tank has Slick Tread Design

Tank projects are great because while every tank design is the same in a fundamental way, there’s nevertheless endless variety in the execution and results. [Hoo Jian Li]’s 3D Printed Tank is smartly laid out and has an unusual tank tread that shows off some slick curves.

The tank itself is remotely controlled over Bluetooth with a custom controller that uses the common HC-05 Bluetooth radio units. The treads are driven by four hobby gearmotors with custom designed wheels, and run over an idler wheel in the center of the body. There isn’t any method of taking up slack in the track and a ripple in the top surface of the track is visible as it drives, but the tank is small enough that it doesn’t seem to mind much. STL files and source code is available on GitHub; unfortunately the repository lacks a wiring diagram but between the low component count, photos, and source code that’s not a show-stopper.

Tank treads see a lot of variation, from 3D printed designs for tracks that use a piece of filament as hinges to an attempt to use a conveyor belt as a tank tread for a go-kart. Some tank projects even eschew treads altogether and go for a screw drive.