LED Sign Brightens Up The Beach After Dark

[Warrior_Rocker’s] family bought a fancy new sign for their beach house. The sign has the word “BEACH” spelled vertically. It originally came with blue LEDs to light up each letter. The problem was that the LEDs had a narrow beam that would blind people on the other side of the room. Also, there was no way to change the color of the LEDs, which would increase the fun factor. That’s why [Warrior] decided to upgrade the sign with multi-colored LEDs.

After removing the cardboard backing of the sign, [Warrior] removed the original LEDs by gently tapping on a stick with a hammer. He decided to use WS2811 LED pixels to replace the original LEDs. These pixel modules support multiple colors and are individually addressable. This would allow for a wide variety of colors and animations. The pixels came covered in a weatherproof resin material. [Warrior] baked the resin with a heat gun until it became brittle. He was then able to remove it entirely using some pliers and a utility knife. Finally, the pixels were held in place with some hot glue.

Rather then build a remote control from scratch, [Warrior] found a compatible RF remote under ten dollars. The LED controller was removed from its housing and soldered to the string of LEDs. It was then hot glued to a piece of cardboard and placed into the sign’s original battery compartment. Check out the video below for a demonstration. Continue reading “LED Sign Brightens Up The Beach After Dark”

Hackaday Prize Entry: Density Altitude Gauge

Despite what extraordinarily overpowered quadcopters suggest, the air pressure of whatever a flying machine flys at is extremely important. Pressure is dependent on altitude and temperature, and there are hundreds of NTSB investigations that have concluded density altitude – pressure altitude corrected for nonstandard temperature variations – was the reason for a crash. Normally density altitude is computed through a slide rule or a flight computer, with the pilot entering in altitude and temperature, but somehow accidents still happen. For his entry to The Hackaday Prize, [Neil McNeight] is building an automated density altitude calculator to automate the process entirely.

Instead of having a pilot enter the altitude and temperature into a flight computer manually, [Neil]’s device grabs the current altitude from a GPS unit, and reads the temperature with a tiny sensor acquired from SparkFun. With just a little bit of math, this device will spit out the altitude an airplane or ‘copter thinks it’s at.

While the FAA won’t allow instruments that are cobbled together on a breadboard, this does have a few applications in the RC world. There are extremely high performance racing quadcopters out there now, and knowing how the craft will perform before flying it will save a few props.

The 2015 Hackaday Prize is sponsored by:

Measuring Temperature On An AVR Without A Sensor

There are a few AVR microcontrollers with onboard temperature sensors. These temperature sensors are neither accurate nor precise, but they do work for a few use cases. [Thomas] came up with a little bit of code that runs on all AVR microcontrollers, and is at least as accurate as the sensors in the rare AVRs that have them.

Although not all AVRs have a temperature sensor, they do all have RC oscillators, and these RC oscillators are temperature sensitive. By combining the RC oscillator and watchdog timer, [Thomas]’ code can get a vague idea if it’s getting hotter or colder.

To prove his code works, [Thomas] took an ATtiny13A chip loaded up with a few bits of code and placed a heated coin on it. The chip was programmed to turn on an LED when it detected a rise in temperature, and predictably, the LED lit up. With a coin chilled in a bowl of ice water, another bit of code ran, flashing the LED.

While we’re sure it’s neither accurate nor precise, it does have its uses – overheating protection or a simple thermostat. You can check out a video of the code in action below.

Continue reading “Measuring Temperature On An AVR Without A Sensor”

DIY RC Hovercraft Makes Batman Action Figure Envious

[Bauwser] had some spare RC Helicopter parts laying around and cobbled together an RC Hovercraft. It worked but not to his liking. That’s okay though, he know it was just a prototype for what was to come; a fully scratch built hovercraft with parts spec’ed out specifically to make it handle the way [Bauwser] wanted.

He started out by sketching out some cool faceted shapes that would both look good and be easy to construct. Sheets of a light but rigid foam were then cut into the appropriate shapes and glued together to create a three-dimensional body. The foam was then covered with a layer of fiberglass and resin to add some strength. A hole was cut in the body to mount a 55mm ducted fan which provides the required air to fill the skirt and lift the vehicle. Another ducted fan is mounted at the back of the craft and points rearward. This ducted fan provides the forward thrust and a servo vectors this fan in order to make turns.

[Bauwser] sewed the skirt himself. It is made out of an old beach tent. The fabric is extremly light and flexible, perfect for a hovercraft. During the test runs, dirt and debris was getting trapped in the skirt tube. A quick trip back to the sewing machine to add some gauze netting fixed that problem and keeps debris collection to a minimum. In the end, [Bauwser] shows what a great DIY RC build can look like with a little planning and experimentation.

Need more DIY RC hovercrafts? Check this out

Video after the break…

Continue reading “DIY RC Hovercraft Makes Batman Action Figure Envious”

Using RC Transmitters With Flight Simulators

It’s winter, and that means terrible weather and very few days where flying RC planes and helicopters is tolerable. [sjtrny] has been spending the season with RC flight simulators for some practice time. He had been using an old Xbox 360 controller, but that was really unsuitable for proper RC simulation – a much better solution would be to use his normal RC transmitter as a computer peripheral.

The usual way of using an RC transmitter with a computer is to buy a USB simulator adapter that emulates a USB game pad through a port on the transmitter. Buying one of these adapters would mean a week of waiting for shipping, so [sjtrny] did the logical thing and made his own.

Normally, a USB simulator adapter plugs in to a 3.5mm jack on the transmitter used for a ‘buddy box’, but [sjtrny] had an extra receiver sitting around. Since a receiver simply outputs signals to servos, this provides a vastly simpler interface for an Arduino to listen in on. After connecting the rudder, elevator, aileron, and throttle signals on the receiver to an Arduino, a simple bit of code and the UnoJoy library allows any Arduino and RC receiver to become a USB joystick.

[sjtrny] went through a second iteration of hardware for this project with a Teensy 3.1. This version has higher resolution on the joystick axes, and the layout of the code isn’t slightly terrible. It’s a great project for all the RC pilots out there that can’t get a break in the weather, and is also a great use for a spare receiver you might have sitting around.

Lego Avengers Assemble to the Helicarrier!

The massive engineering-defying Helicarrier from the Avengers is a brilliant work of CGI. Too bad it’d never actually fly… Like… Never.

Luckily, that didn’t stop our favorite RC hackers over at FliteTest from making a scale model of it — that actually works! If you’re not familiar, the Helicarrier is a fictional ship, the pride of S.H.I.E.L.D’s air force, or is it their navy.

It’s a massive aircraft carrier with four huge repulsor engines built into it, borrowing tech from Stark Industries. The shear size of it is what makes it completely ridiculous, but at the same time, it’s also unbelievably awesome.

Unfortunately, repulsor technology doesn’t seem to exist yet, so the FliteTest crew had to settle with a set of 8 brushless outrunner motors, with two per “engine”. The whole thing is almost 6′ long.

It doesn’t handle that well (not surprising!) but they were able to launch another RC  plane off of it, mid-flight! Landing however… well you’ll have to watch the video. Continue reading “Lego Avengers Assemble to the Helicarrier!”

R/C Wheel Loader Clears Snow, Lifts People

For some people, R/C cars just aren’t enough. [djMedic2008] has gotten his hands on a monstrous 1/5 scale wheel loader. The loader weighs in at 500lbs, and can lift up to 250 lbs. It was built several years ago as a prototype by [Richard] at Tiny Titan Earth Movers.

The design is based upon huge machines made by companies like Caterpillar and Komatsu. The 4WD system is driven a DC motor through a worm gear reduction. Bucket operation and steering are both operated by a hydraulic system driven by an electric pump. Just like the full-scale machines, the mini loader uses an articulated steering system. The front wheels are locked in place while the entire chassis bends at the middle pivot point. This allows for a much stronger solid front axle.

loader-gearAfter several years of hard life, the loader came to [djMedic] in need of some TLC. The biggest issue was that the rear axle bevel gear had lost several teeth. This gear is under enormous loads when the loader is turning. A gear made of harder steel was the easy answer. Thankfully, you can order high carbon steel bevel gears from Amazon. The repair video gives us a look at the design of the loader. The main components of the machine are welded up from steel sheet and tube stock. This means that [djMedic] won’t have a hard time finding spare parts for his machine once he puts it to work clearing snow, dirt, or anything else that gets in its way!

Click past the break to see the loader in action!

Continue reading “R/C Wheel Loader Clears Snow, Lifts People”