Breathing New Life Into An Old Key

February 21, 2016 by Jenny List 13 Comments

For most of us who have experimented with Morse code, the oldest key we are likely to have used will have been a piece of military surplus kit from the Second World War era. [Kyle Gabriel] however is a lucky man. His grandfather left him his key-on-board telegraph practice set, a vintage key and telegraph sounder arrangement used to learn Morse code in the days when the telegraph was king. Rather than keep the set merely as an heirloom, [Kyle] set about bringing it up to date by interfacing it to a Raspberry Pi and writing a Morse reader program.

Along the way [Kyle] had to contend with debouncing the switching signal from the key, considering an RC network before settling on a software debounce timer. He provides a brief synopsis of the mechanics of Morse decoding software, and a demonstration of the code in action which you can see in the video below the break.

[Kyle’s] decoding software, beatbybeat, is on GitHub. We can see it will be a useful tool for anyone interested in Morse, or who is writing their own Morse software.

Morse code has featured on these pages more than a few times over the years. Of relevance to this piece are an Arduino decoding Morse code, a more up-to-date practice oscillator with a home-made key, and a couple of other vintage telegraphs reading RSS feeds and reading emails.

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TV Control With Hand Gestures

February 17, 2016 by Will Sweatman 12 Comments

The cell phones of yesteryear were covered in buttons. Today’s cell phones are mostly a touch display with maybe one or two buttons. As time marches on, we find ourselves using our fingers more for gestures and swipes than button pushing to control our devices. Sadly, the television remote has been stuck in an antiquated state and most are still covered in archaic buttons.

[Frederick] has decided to dig the TV remote out from the stone age and updated it to use simple gestures for control. We’ve seen gesture control before, but this one is certainly the most elegant. He’s using a Raspberry Pi with a Skywriter HAT gesture recognition board. The driver is super easy to install and can be done in a single command line. The Skywriter hat interpreters the hand gesture and the Pi fires the appropriate signal via an IR emitter. This approach made the project fairly simple to put together, with surprisingly good results.

Be sure to check out his blog for all code needed, and take a look at the video below to see the remote in action.
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A Quadcopter Controlled By A Pi Zero

February 16, 2016 by Brian Benchoff 57 Comments

Flight controllers for quadcopters and other drones are incredible pieces of engineering. Not only do these boards keep an aircraft level, they do so while keeping the drone in one place, or reading a GPS sensor and flying it from waypoint to waypoint. The latest of these flight controllers is built on everyone’s favorite $5 computer, the Raspberry Pi Zero.

The PXFmini controller and autopilot shield is the latest project from Erle Robotics that puts eight servo outputs on the Pi, barometer and IMU sensors, a power supply, and all the adapters to turn the Raspberry Pi Zero into a capable flight controller. Since the Pi Zero will have some computational horsepower left over after keeping a quadcopter level, there’s a possibility of some very cool peripherals. Erle Robotics has been working with depth cameras and Lidar on more than a few drones. This makes for some interesting applications we can only imagine now.

The schematics for the PXFmini are open source in the best traditions of the RC and drone community and will be available soon. You can check out a video of the FXPmini flying around an office below.

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The Internet Of Cats

February 15, 2016 by James Hobson 70 Comments

With the miniaturization of technology, we’re now able to do some pretty crazy things with computers the size of credit cards. [Dennis] has been working on a rather unique project — he calls it the Cat Exploit — we call it the Internet of Cats.

By making pet-wearable tech (is that a new term?), it’s possible to create a mini war-driving server that stray cats (or other small animals) could wear. As they roam the streets, their feline-augmentation searches and taps into open or badly secured WiFi networks, repeating and spreading the signal to other Server Entities (other network-enabled cats), opening up the networks for all to use. Continue reading “The Internet Of Cats” →

Controlling RGB LEDs With The Pi Zero

February 14, 2016 by Brian Benchoff 22 Comments

The Pi Zero is a great piece of hardware, even if you’re not designing another USB hub for it. [Marcel] wanted to control a few RGB LED strips from his phone, and while there are a lot of fancy ways you can do this, all it really takes is a Pi Zero and a few parts that are probably already banging around your parts drawers.

This isn’t a project to control individually addressable RGB LEDs such as NeoPixels, WS2812s, or APA102 LEDs. This is just a project to control RGB LEDs with ~~five~~ four connectors: red, green, blue, power, ~~and~~ or ground. These are the simplest RGB LEDs you can get, and sometimes they’re good enough and cheap enough to be the perfect solution to multi-colored blinkies in a project.

Because these RGB LEDs are simple, that means controlling them is very easy. [Marcel] is just connecting a transistor to three of the PWM pins on the Pi and using a TIP122 transistor to drive the red, green, and blue LEDs. You’ve got to love those TIPs package parts!

Control of the LEDs is accomplished through lighttpd. This does mean a USB WiFi dongle is required to control the LEDs over the Internet, but it is so far the simplest way we’ve seen to add multicolor blinkies to the web.

The Raspberry Pi Zero contest is presented by Hackaday and Adafruit. Prizes include Raspberry Pi Zeros from Adafruit and gift cards to The Hackaday Store!
See All the Entries || Enter Your Project Now!

Ridiculously Automated Dorm Room

February 13, 2016 by Al Williams 22 Comments

Take three NRF24L0+ radios, two Arduino Nanos, and a Raspberry Pi. Add a bored student and a dorm room at Rice University. What you get is the RRAD: Rice Ridiculously Automated Dorm. [Jordan Poles] built a modular system inspired by BRAD (the Berkeley Ridiculously Automated Dorm).

RRAD has three types of nodes:

Actuation nodes – Allows external actuators like relays or solenoids
Sensory nodes – Reports data from sensors (light, temperature, motion)
Hub nodes – Hosts control panel, records data, provides external data interfaces

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Hacklet 95 – More Pi Zero Contest Entries

February 13, 2016 by Adam Fabio 8 Comments

We’re well into the second week of the Hackaday and Adafruit ultimate team-up: The Raspberry Pi Zero Contest. The entries have been flying in! As of Thursday evening, we have 70 projects vying for one of 10 Raspberry Pi Zeros, and one of three $100 gift certificates to The Hackaday Store. This week on The Hacklet, we’re going to take a look at a few more contest entries.

We start with [Sean Hodgins] and Blueberry Zero – Keep your Pi in your Pocket. [Sean] can’t leave home without his Raspberry Pi Zero. Carrying all the cables, adapters, and accessories required to power up a tiny Linux computer can be a chore though. He’s created a solution to simplify all that with Blueberry Zero. This custom PCB hat contains an HC-05 style Bluetooth module connected to the Pi’s console port. Serial alone doesn’t make for a standalone Pi, so [Sean] added a LiPo battery and charger chip. A switching power supply boosts the 4.2 V LiPo output up to the 5 V required for the Pi. Now when [Sean] just has to hack out some python code, all he needs to do is open a Bluetooth connection from a cell phone, tablet, or computer.

[Doihaveto] is using his Pi Zero to manage a desktop PC. PC Power allows him to not only turn his computer on or off, but to disconnect the mains power completely. [Doihaveto’s] PC does have Wake On Lan, but he’s run into problems when the system has failed. His Pi provides an extra layer of protection in case things don’t wake up as expected. The board contains two optoisolated connections to a host PC. One is the power switch output, the other is the power LED input. If all else fails, PC Power also can control a solid state relay to completely isolate the computer from mains power. PC Power uses a web interface created with Python using the flask web framework.

Next up is [tomwsmf] with PiFold. Like [Sean] up above, [tomwsmf] can’t leave home without his Pi Zero. Rather than hacking code though, [tomwsmf] is serving up media. PiFold is a wallet containing a Pi Zero powered server. The Anyfesto software package runs on the Pi, serving up songs and files via WiFi. Audio is also transmitted on 88.1 MHz FM via PiFM. A 2500 mAh battery pack coupled with a boost converter keeps PiFold humming away. When the battery needs a charge, [tomwsmf] can use a small solar panel to top up the battery while staying green.

Finally, we have [Fredrik J] with Retrofit Robot. The 1980’s were a golden age of toy robots from Japan. Tomy, Nikko, and a few other companies created devices like Omnibot, which were ahead of their time. [Fredrick] still has his vintage Nikko RC-ROBOT, but it has long since ceased to function. The Pi Zero presents a perfect opportunity to give the little guy a new lease on life. [Fredrik’s] goal is to keep the RC-ROBOT’s original look while giving him new functions. The old DC motors are being replaced with closed loop servos. The servos will be controlled by an Adafruit 16 channel servo driver board. The next step for Retrofit Robot is a big 6000 mAh battery. We can’t wait to see how this one turns out!

If you want to see more entrants to Hackaday and Adafruit’s Pi Zero contest, check out the submissions list! If you don’t see your project on that list, you don’t have to contact me, just submit it to the Pi Zero Contest! That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!