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.

Continue reading “Breathing New Life Into An Old Key” →

Hacklet 96 – Pi Zero Contest Projects Week 3

February 20, 2016 by Adam Fabio 3 Comments

The calendar is rolling through the third week of the house that Hackaday and Adafruit built: The Raspberry Pi Zero Contest. We’re nearly at 100 entries! Each project is competing 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.

[Phil “RzR” Coval] is trying to Port Tizen to the Raspberry Pi Zero. For those not in the know, Tizen is an open source operating system for everything. Billed as a go-to OS for everything from wearables to tablets to smartphones to in-vehicle entertainment systems, Tizen is managed by the Linux Foundation and a the Tizen Association. While Tizen works on a lot of devices, the Raspberry Pi and Pi 2 are still considered “works in progress”. Folks are having trouble just getting a pre-built binary to run. [Phil] is taking the source and porting it to the limited Pi Zero platform. So far he’s gotten the Yocto-based build to run, and the system starts to boot. Unfortunately, the Pi crashes before the boot is complete. We’re hoping [Phil] keeps at it and gets Tizen up and running on the Pi Zero!

Next up is [shlonkin] with Classroom music teaching aid. Guitar Hero has taught a generation of kids to translate flashing lights to playing notes on toy instruments. [Shlonkin] is using similar ideas to teach students how to play real music on a harmonica. The Pi Zero will control a large display model of a harmonica at the front of the classroom. Each hole will light up when that note is to be played. Harmonica’s have two notes per hole. [Shlonkin] worked around this with color. Red LEDs mean blow (exhale), and Blue LEDs mean draw (inhale). The Pi Zero can do plenty more than blink LEDs and play music, so [shlonkin] plans to have the board analyze the notes played by the students. With a bit of software magic, this teaching tool can provide real-time feedback as the students play.

[Spencer] is putting the Pi Zero to work as a $5 Graphics Card For Homebrew Z80. The Z80 in this case is RC2014, his DIY retro computer. RC2014 was built as part of the 2014 RetroChallenge. While the computer works, it only has an RS-232 serial port for communication to the outside world. Unless you have a PC running terminal software nearby, the RC2014 isn’t very useful. [Spencer] is fixing that by using the Pi Zero as a front end for his retro battle station. The Pi handles USB keyboard input, translates to serial for the RC2014, and then displays the output via HDMI or the composite video connection. The final design fits into the RC2014 backplane through a custom PCB [Spencer] created with a little help from kicad and OSHPark.

Finally we have [txdo.msk] with 8 Leaf Pi Zero Bramble. At $5 each, people are scrambling to build massively parallel supercomputers using the Raspberry Pi Zero. Sure, these aren’t practical machines, but they are a great way to learn parallel computing fundamentals. It only takes a couple of connectors to get the Pi Zero up and running. However, 8 interconnected boards quickly makes for a messy desk. [Txdo.msk] is designing a 3D printed modular case to hold each of the leaves. The leaves slip into a bramble box which keeps everything from shorting out. [Txdo.msk] has gone through several iterations already. We hope he has enough PLA stocked up to print his final design!

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!

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.
Continue reading “TV Control With Hand Gestures” →

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.

Continue reading “A Quadcopter Controlled By A Pi Zero” →

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

Continue reading “Ridiculously Automated Dorm Room” →

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!

Swarm Of Robot Boats Coming To An Ocean Near You Soon

February 12, 2016 by Richard Baguley 31 Comments

Planning a hostile takeover of your local swimming pool? This might help: [Dr Anders Lyhne Christensen] sent us a note about his work at the BioMachines Lab of the Institute of Telecommunications in Portugal. They have been building a swarm of robot boats to experiment with autonomous swarms, with some excellent results.

In an autonomous swarm, each robot makes its own decisions and talks to its neighbors, and the combined behavior of the swarm produces an overall behavior, like ants in a nest. They’ve created swarms that can autonomously navigate, patrol an area or monitor the temperature in an area and return to base to report the results. In an excellent video, [Anders] outlines how they used computational evolution to create these behaviors, randomly mutating a neural net to find the best approach, which is then sent to the real boats.

Perhaps coolest of all: the whole project is open source, with the brains of each boat running on a Raspberry Pi, and a CNC milled foam hull with 3D printed component mounts. Each boat costs about 300 Euro (about $340), but you could reduce the cost a bit by salvaging components and once the less-expensive Pi Zero becomes obtainable. This project will no doubt be useful for many an evil genius who is sick of being splashed by the toughs at the local pool: a swarm of killer robots surrounding them would be an excellent way to keep them at bay.

Continue reading “Swarm Of Robot Boats Coming To An Ocean Near You Soon” →