Extrinsic Motivation: Smart Antenna Tracker For R/C Aircraft

September 1, 2014 by Adam Fabio 20 Comments

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.

Hacklet #13 – Chopper Royalty

August 29, 2014 by Adam Fabio 7 Comments

This week’s Hacklet focuses on two wheeled thunder! By that we mean some of the motorcycle and scooter projects on Hackaday.io.

We’re going to ease into this Hacklet with [greg duck’s] Honda Sky Restoration. Greg is giving a neglected 15-year-old scooter some love, with hopes of bringing it back to its former glory. The scooter has a pair of stuck brakes, a hole rusted into its frame, a stuck clutch, and a deceased battery, among other issues. [Greg] already stripped the body panels off and got the rear brake freed up. There is still quite a bit of work to do, so we’re sure [Greg] will be burning the midnight 2 stroke oil to complete his scooter.

Next up is [Anders Johansson’s] jaw dropping Gas turbine Land Racing Motorcycle. [Anders] built his own gas turbine engine, as well as a motorcycle to go around it. The engine is based upon a Garrett TV94, and directly powers the rear wheel through a turboshaft and gearbox. [Anders] has already taken the bike out for a spin, and he reports it “Pulled like a train” at only half throttle. His final destination is the Bonneville salt flats, where he hops to break the 349km/h class record. If it looks a bit familiar that’s because this one did have its own feature last month.

[GearheadRed] is taking a safer approach with FireCoates, a motorcycle jacket with built-in brake and turn signal indicators. [GearheadRed] realized that EL wire or LED strip wouldn’t stand up to the kind of flexing the jacket would take. He found his solution in flexible light pipes. Lit by an LED on each end, the light pipes glow bright enough to be seen at night. [GearheadRed] doesn’t like to be tied down, so he made his jacket wireless. A pair of bluetooth radios send serial data for turn and brake signals generated by an Arduino nano on [Red’s] bike. Nice work [Red]!

[Johnny] rounds out this week’s Hacklet with his $1000 Future Tech Cafe Racer From Scratch. We’re not quite sure if [Johnny] is for real, but his project logs are entertaining enough that we’re going to give him the benefit of the doubt. Down to his last $1000, [Johnny] plans to turn his old Honda xr650 into a modern cafe racer. The new bike will have electric start, an obsolete Motorola Android phone as its dashboard, and a 700cc hi-comp Single cylinder engine at its heart. [Johnny] was last seen wandering the streets of his city looking for a welder, so if you see him, tell him we need an update on the bike!

That’s it for this week. If you liked this installment check out the archives. We’ll see you next week on The Hacklet – bringing you the Best of Hackaday.io!

Droning On: Maiden Flights

August 28, 2014 by Adam Fabio 4 Comments

When we last left off, the Hackaday Drone Testbed was just a box of parts on workbench. Things have changed quite a bit since then! Let’s get straight to the build.

With the arms built and the speed controls soldered up, it was simply a matter of bolting the frame itself together. The HobbyKing frame is designed to fold, with nylon washers sliding on the fiberglass sheets. I don’t really need the folding feature, so I locked down the nylock nuts and they’ve stayed that way ever since. With the arms mounted, it was finally starting to look like a quadcopter.

Using the correct screws, the motors easily screwed into the frames. I did have to do a bit of filing on each motor plate to get the motor’s screw pattern to fit. The speed controls didn’t have a specific mount, so I attached them to the sides of the arms with double-sided tape and used some zip ties to ensure nothing moved. In hindsight I should have mounted them on the top of the arms, as I’m planning to put LED light strips on the outside of edges of the quad. The LEDs will help with orientation and ensure a few UFO sightings during night flights.

Power distribution is a major issue with multicopters. Somehow you have to get the main battery power out to four speed controls, a flight controller, a voltage regulator, and any accessories. There are PCBs for this, which have worked for me in the past. For the Hackaday Testbed, I decided to go with a wiring harness. The harness really turned out to be more trouble than it was worth. I had to strip down the wires at the solder joint to add connections for the voltage regulator. The entire harness was a bit longer than necessary. There is plenty of room for the excess wire between the main body plates of the quad, but all that copper is excess weight the ‘bench’ doesn’t need to be carrying. The setup does work though. If I need to shed a bit of weight, I’ll switch over to a PCB.

Click past the break to read the rest of the story.

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LED Water Wheel Display Is Dekatron-tastic!

August 27, 2014 by Adam Fabio 10 Comments

led-ring-final

Sometimes, it’s the simple things that mesmerize. [JohnS_AZ] has created a simple dekatron style LED ring, but we can’t seem to stop watching his video. [John’s] LED ring began as a visual indicator for his Hackaday Prize entry, a water consumption display. Judging by his website, [John] is a bit of a display nut. Nixie tubes and huge clocks feature prominently.

We’ve seen plenty of LED projects using the trusty 74xx595 8-bit shift register. [John] personally isn’t a fan, as the entire chip is only rated to drive about 50mA. While hackers routinely push the chip several times past this limit, [John] found a chip designed for the task in the Texas Instruments TLC59282 16 channel constant current LED driver. (PDF link) While more expensive than the ‘595, the 59282 makes life much easier. Only one resistor is needed at the chip’s current sense pin, rather than a current-limiting resistor for each LED. The 59282 also provides a blank input, which is perfect for driving with PWM.

[John] designed a simple PCB with a the 59282 driving a ring of 16 LEDs. While he waited for the boards to come in, he wrote some test code for a Microchip PIC16F1509. [John’s] code is not optimized, but that makes it easy to see exactly which bit patterns he’s writing to the LEDs. It all makes for a great demo, and reminds us of those old Dekatron tubes.
It’s the demo video that makes this project. Click past the break and give it a watch. After several long days of judging entries, a really nice LED ring might be just what the doctor ordered.

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Hacklet #12 – Last Minute Hackaday Prize Submissions

August 22, 2014 by Adam Fabio 10 Comments

If hackers and engineers are notorious for anything, it’s for procrastinating. Many of us wait until the absolute last-minute to get things done. The Hackaday Prize has proved to be no exception to that. Anyone watching the newest projects could see the entries fly in the last few days. Let’s take a quick look at a few.

[Cyrus Tabrizi] submitted Handuino just a few short hours before the deadline. Handuino is an Arduino based human interface device. You can use it to control anything from R/C cars to 3D printers, to robots to Drones. Input is through the joystick, switches, and buttons, and output through the on-board 2.2″ LCD. Projects can interface to the Handuino via a USB port, or an XBEE radio. Nice Work [Cyrus].

[txyz.info] wants to make us more human than human with Bionic Yourself, an implantable device to make you a bionic superhero. [txyz] plans to use sensors such as an electromagnetic field sensor, accelerometers, and Electromyography (EMG) muscle activity detectors. The idea is to not only sense the implanted wearer, but the world around them. The wearer can then use an embedded Bluetooth radio to send commands. The entire system runs on the Arduino platform, so updating your firmware will be easy. Not everyone has a charging port, so [txyz] has included wireless battery charging in the system.

[Laurens Weyn] wants to wake us all up with Overtime: the internet connected alarm clock. Overtime is a Raspberry PI powered clock with a tower of 7 segment displays. The prototype displays were sourced from an old exchange rate sign. Overtime does all the normal clock things, such as display the time, and date. It even allows you to set and clear alarms. The display is incredible – there are enough pixels there to play Tetris. Overtime is currently running on an Arduino Mega, but [Laurens] plans to move to a Raspberry PI and hook into the internet for information such as Google calender events.

We’re going to cut things a bit short this week. Your work is done (for now) but for the Hackaday staff, the work is just beginning. We’re already on task, reviewing the entries, and picking which submissions will move on to the next round. Good luck to everyone who entered.

As always, See you in next week’s Hacklet. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Sparkfun Ships 2000 MicroViews Without Bootloaders

August 21, 2014 by Adam Fabio 47 Comments

Everyone has a bad day right? Monday was a particularly bad day for the folks at Sparkfun. Customer support tickets started piling up, leading to the discovery that they had shipped out as many as 1,934 MicroViews without bootloaders.

MicroView is the tiny OLED enabled, Arduino based, microcontroller system which had a wildly successful Kickstarter campaign earlier this year. [Marcus Schappi], the project creator, partnered up with SparkFun to get the MicroViews manufactured and shipped out to backers. This wasn’t a decision made on a whim, Sparkfun had proven themselves by fulfilling over 11,000 Makey Makey boards to backers of that campaign.

Rather than downplay the issue, Sparkfun CEO [Nathan Seidle] has taken to the company blog to explain what happened, how it happened, and what they’re going to do to make it right for their customers. This positions them as the subject of our Fail of the Week column where we commiserate instead of criticize.

First things first, anyone who receives an affected MicroView is getting a second working unit shipped out by the beginning of November. Furthermore, the bootloaderless units can be brought to life relatively easily. [Nate] provided a hex file with the correct bootloader. Anyone with an Atmel AVR In-System Programming (ISP) programmer and a steady hand can bring their MicroView to life. Several users have already done just that. The bootloader only has to be flashed via ISP once. After that, the MicroView will communicate via USB to a host PC. Sparkfun will publish a full tutorial in a few weeks.

Click past the break to read the rest of the story.

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When Worlds Collide: 68008 Bootstrapped By An Arduino Uno

August 21, 2014 by Adam Fabio 23 Comments

68008-ardu

[Peter Bjornx] brings classic microprocessors and modern microcontrollers together with his Arduino bootstrapped 68008 computer. The Motorola 68008 is the 8-bit external bus version of the well-known 68000 (or 68k) microprocessor. A friend gave [Peter] one of these chips, so he built a simple computer around it.

This isn’t one of those clean retrocomputers with every connection carefully planned out and wire wrapped. [Peter’s] created a true hack – a working 68k system on a breadboard created with whatever he had on hand at the time. The real gem of this system is the ROM. [Peter] replaced an EPROM chip with an Arduino.

In the not-so-good-old-days, microprocessors (and many microcontrollers) ran from an external ROM chip. This often was a UV-erasable EPROM. Carefully compiled code was burned into the EPROM with a device programmer. If the code wasn’t perfect, the EPROM had to be pulled and placed under a UV lamp for 20 minutes or so to erase it before it was time to try again. EPROM emulators were available, but they were way too expensive for the hobbyist.

Thankfully those days are far behind us now with the advent of EEPROM and then Flash. [Peter] didn’t want to revisit the past either, so he wrote a simple Arduino sketch which allowed it to act as an EPROM emulator, including address logging via the serial port.

The design still caused [Peter] some headaches, though. His major problem was a classic 68k issue, /DTACK timing. /DTACK or Data Transfer Acknowledge is one of several bus control signals used by the 68k. When the 68k performs a read from the data bus, it waits for /DTACK before it transfers data. The Arduino was too slow to release /DTACK in this case, which caused the 68k to think every read was immediately completed. There is a much clearer explanation of the 68k bus cycles on this Big Mess O Wires page. [Peter’s] solution was simple – a D flip-flop connected to the address strobe took care of the timing issues.

It took quite a bit of tinkering, but the system eventually worked. Peter was able to run the 68008 from its reset vector into a simple loop using the Arduino. It’s only fitting that the 68k program loaded by the Arduino was an LED blinker, everyone’s favorite hardware Hello World.

Thanks [Robert!]