Hackaday Links: March 1, 2015

The somewhat regular Hardware Developers Didactic Galactic was a few days ago in San Francisco. Here’s the video to prove it. Highlights include [James Whong] from Moooshimeter, the two-input multimeter, [Mark Garrison] from Saleae, and a half-dozen other people giving talks on how to develop hardware.

[Taylor] made a portable NES with a retron, a new-ish NES clone that somehow fits entirely in a glop top IC. The controllers sucked, but [Taylor] made a new one with touch sensors. All that was required was eight transistors. The enclosure is an Altoid tin, and everything works great.

Here’s a YouTube channel you should subscribe to: Ham College. The latest episode covers the history of radio receivers and a crystal radio demonstration. They’re also going through some of the Technical class question pool, providing the answers and justification for those answers.

[Prusa] just relaunched prusaprinters and he’s churning out new content for it. Up now is an interview with [Rick Nidata] and his awesome printed container ship.

The tip line is overflowing with ESP8266 breakout boards. Here’s the simplest one of them all. It’s a breadboard adapter with stickers on the pin headers. Turn that into a right-angle breadboard adapter, and you’ll really have something.

Here’s something that’s a bit old, but still great. [Dillon Markey], one of the stop-motion animators for Robot Chicken modified a Nintendo Power Glove for animation duties. It seems to work great, despite being so bad. Thanks [Nicholas] for the link.

[David] the Swede – a consummate remote control professional we’ve seen a few times before – just flew his tricopter in a mall so dead it has its own Wikipedia page. Awesome tricopter, awesome location, awesome video, although we have to wonder how a few really, really bright LEDs would make this video look.

Here’s an item from the tip line. [Mark] wrote in with an email, “Why do you put names in [square brackets] in the blog entries? Just curious.” The official, [Caleb]-era answer to that question is that sometimes people have bizarre names that just don’t work in text. Imagine the sentence, “[12VDC] connected the wires to the terminal” without brackets. The semi-official answer I give is, “because.”

DIY Head Mounted Display Based On Movie Based On Stephen King Story

Ever since [will1384] watched “The Lawnmower Man” as a wee lad, he’s been interested in virtual reality. He has been messing around with it for years and even had a VictorMaxx Stuntmaster, one of the first available head mounted displays. Years later, the Oculus Rift came out and [will1384] wanted to try it out but the $350 price tag put it just out of his price range for a discretionary purchase. He then did what most of us HaD readers would do, try building one himself, and with a goal for doing it for around $100.

The main display is a 7″ LCD with a resolution of 1024×600 pixels and has a mini HDMI input. Some DIY head mounted display projects out on the ‘web use ski goggles or some sort of elastic strap to hold the display to the wearer’s head. [will1384] took a more industrial approach, literally. He used the head mounting system from a welding helmet. This not only has an adjustable band but also has a top strap to prevent the entire contraption from sliding down. Three-dimensional parts were printed out to secure the LCD to the welding helmet parts while at the same time creating a duct to block out external light.


Inside the goggles are a pair of 5x Loupe lenses mounted between the user’s eyes and the LCD screen. These were made to be adjustable so that the wearer can dial them in for the most comfortable viewing experience. The remote mounted to the top strap may look a little out-of-place but it is actually being used to capture head movement. In addition to a standard wireless remote, it is also an air mouse with internal gyroscopes.

An Extremely Tiny 5.8GHz FPV Transmitter

Flying RC aircraft with a first person view is the latest and greatest thing in the hobby. In a fact that I’m sure will be shocking to 90% of people, you don’t need to buy a Phantom quad fly FPV. The guys at Flite Test show how you can build a tiny 5.8GHz FPV transmitter for under $100.

The parts used for this build are pretty much jelly bean parts at this point, but [Peter] at Flite Test is going for extremely lightweight parts for this build. He found an NTSC board camera that only weighs 1g and added a wide-angle lens. The transmitter is a tiny 200mW module that only weighs about 2g.

Why are the Flite Test crew going for small and light FPV setups? They just launched a new line of planes that can be built from a single piece of foam board. If you have a small micro quad, you can easily add FPV to it with this rig.

Complete FPV Setup for Your Drone

[Ioannis] is like anyone else who has a quadcopter or other drone. Eventually you want to sit in the cockpit instead of flying from the ground. This just isn’t going to happen at the hobby level anytime soon. But the next best option is well within your grasp. Why not decouple your eyes from your body by adding a first-person video to your quad?

There are really only four main components: camera, screen, and a transceiver/receiver pair to link the two. [Ioannis] has chosen the Sony Super HAD CCTV camera which provides excellent quality at the bargain basement price of just $25 dollars. A bit of patient shopping delivered a small LCD screen for just $15. The insides have plenty of room as you can see. [Ioannis] connected the screen’s native driver board up to the $55 video receiver board. To boost performance he swapped out the less-than-ideal antenna for a circular polarized antenna designed to work well with the 5.8 GHz radio equipment.

It seems that everything works like a dream. This all came in under $100 which is half of what some other systems cost without a display. Has anyone figured out a way to connect a transmitter like this to your phone for use with Google Cardboard?

Controlling a Block Camera with an RC Transmitter

The world of drones and FPV remote-controlled aircraft is rapidly expanding, airframes are getting bigger, and the demand for even cooler AV gear is higher than ever. [elad] got his hands on a Sony block camera that is able to zoom in on a scene – great if you want to get close to the action while still flying a safe distance away. Controlling the zoom on these cameras is usually done through RS232, but [elad] made it work with an RC transmitter.

The camera [elad] is using is a Sony FCB-EX11D block camera with a standard SD resolution sensor. This camera has 10x optical zoom, making it a great solution to aerial surveillance, the only problem being the RS232 connection and the VISCA protocol. [elad] used an Arduino to listen in on the elevator channel from an RC receiver, translating that to something the camera will understand. The result is a controllable zoom on a camera that could easily take to the skies.

The entire camera package, with Arduino and electronics included, weighs in at about 100 grams. That’s about the same as a GoPro, and would fit perfectly on a camera gimbal. The only problem is getting a transmitter with enough channels or someone else to operate the camera while flying. Video below.

Continue reading “Controlling a Block Camera with an RC Transmitter”

DIY FPV Goggles Born From Necessity of Cheapness

So now that you’ve built your quadcopter and can fly it without crashing most of the time, what’s next? How about metaphorically hopping into the pilot’s seat with a First Person View setup. Great idea… but the cost of the required gear can be a deal breaker. FPV goggles alone range from the low to high hundreds. [sneaky] was using his laptop screen for his FPV setup and decided to try to make is own FPV goggles.

The display is just a small LCD screen that was purchased off eBay. Craft foam board was cut, bent, glued and duct taped to form a box about the same size as the LCD screen which is also secured to the box with duct tape. [sneaky] then cut the opposite side of the box to fit his face before he lined it with 1/2″ weatherstripping foam. Staring at an LCD screen just inches from your face is sure to cause some discomfort. A Fresnel lens inserted in between the user’s eyes and the LCD reduces eye strain to make long flights tolerable. The whole assembly is then held to your noggin via a recycled ski goggle strap.

In the end, [sneaky] likes his new goggles better than his old laptop screen and sun shade setup. The goggles aren’t too heavy and he can wear them comfortably for a while. We’ve seen a DIY FPV goggle setup in the past that uses individual lenses for each eye rather than one large Fresnel lens.

Extrinsic Motivation: Smart Antenna Tracker for R/C Aircraft

Long distance FPV (First Person View) flying can be a handful. Keeping a video feed alive generally requires a high gain directional antenna. Going directional creates the chore of keeping the antenna pointed at the aircraft. [Brandon’s] smart antenna tracker is designed to do all that automatically. What witchcraft is this, you ask? The answer is actually quite simple: Telemetry! Many flight control systems have an optional telemetry transmitter. [Brandon] is using the 3DRobotics APM or PixHawk systems, which use 3DR’s 915 MHz radios.

The airborne radio sends telemetry data, including aircraft latitude and longitude down to a ground station. Equipped with a receiver for this data and a GPS of its own, the smart antenna tracker knows the exact position, heading and velocity of the aircraft. Using a pan and tilt mount, the smart antenna tracker can then point the antenna directly at the airborne system. Since the FPV antenna is co-located on the pan tilt mount, it will also point at the aircraft and maintain a good video link.

One of the gotchas with a system like this is dealing with an aircraft that is flying directly overhead. The plane or rotorcraft can fly by faster than the antenna system can move. There are a few commercial systems out there that handle this by switching to a lower gain omnidirectional whip antenna when the aircraft is close in. This would be a great addition to [Brandon’s] design.