Google Contest Builds More Efficient Inverters

A few summers ago, Google and IEEE announced a one million dollar prize to build the most efficient and compact DC to AC inverter. It was called the Little Box Challenge, with the goal of a 2kW inverter with a power density greater than 50 Watts per cubic inch.

To put this goal into perspective, the DC inverter that would plug into a cigarette lighter in your car has a power density of about 1 or 2 Watts per cubic inch. Very expensive inverters meant for solar installations have a power density of about 5 Watts per cubic inch. This competition aimed to build an inverter with ten times the power density of what is available today.

Now, the results are in, and the results are extremely surprising. The best entry didn’t just meet the goal of 50 W/in³, it blew the goal out of the water.

The winning entry (PDF) comes from CE+T Power, and comes in a package with a volume of 13.77 in³. That’s a power density of 143 W/in³ for a unit you can hold in the palm of your hand. The biggest innovations come from the use of GaN transistors and an incredible thermal management solution.

Other finalists for this competition include Schneider Electric Team from France that managed a 100 W/in³ and a Virginia Tech team that managed a power density of 61.2 W/in³.

Thanks [wvdv2002] for the tip.

Bringing Nautical Charts To A Sunlight Readable Display

Road atlases are still published, but you wouldn’t know it if you have a smartphone and Google Maps. Most pilots who got their license a decade ago started on paper maps, but the iPad rules the cockpit today. On a single SD card, you can store maps for every square mile of the Earth’s surface. [Erland] figured it was high time for digital maps to go nautical and built a tablet-like device to display charts while sailing.

The Pi Chart is, of course, powered by a Raspberry Pi running a few dozen lines of JavaScript and HTML. Software wise, there’s not much to this build save for the new OpenGL-based rendering that allows for ultra smooth map rendering.

The hardware is where this build becomes useful, and for that, [Erland] is using a sunlight readable Pixel Qi display. A Li Ion battery provides about 10 hours of runtime, and a Bluetooth enabled GPS dongle tells the Pi exactly where the boat is.

Continue reading “Bringing Nautical Charts To A Sunlight Readable Display”

Raspberry Pi Zero Round 1 Winners!

The Raspberry Pi Zero Contest presented by Adafruit and Hackaday has been going incredibly well! We currently have 132 projects entered, and there is still time for YOU to get in on the fun! The only problem entrants have had is getting their hands on these amazing $5 computers. We’ve made that easy by giving away ten Raspberry Pi Zero boards. The following projects were well documented, well thought out projects were selected by the judges. We’ve already informed the winners through, and will be shipping out the Pi Zero boards to them right away.

Please join the judges and the entire Hackaday staff in congratulating the winners of the Pi Zero boards!

If you didn’t win, all is not lost! There is still time to enter the contest. The deadline is 11:59 pm PST on March 13, 2016. You’ll be in the running for one of three $100 gift certificates to The Hackaday Store!

Punch Card Reader for the 10 Types of People in the World

Punch card data input is so 1890 US Census, right? Maybe not, if your goal is to educate kids about binary numbers and how they can encode characters. In which case, this paper clip and metal tape punch card reader might be just the thing you need.

Built as part of the educational outreach efforts of the MakeICT hackerspace, this project allows kids and adults to play with binary numbers and get some instant feedback. The reader itself is a simple affair of wood and plastic; bent paperclips make contact with a foil tape strip and LEDs show the state of the five input bits. A card is provided to students with spaces for the letters of a word that they want to input, along with a table to translate each letter into a number. Students use a paper punch to encode each character in binary. As the card is pulled through the reader, the letters are spoken by the Pi in turn and the whole word is pronounced at the end.

We’ll no doubt hear quibbles with the decision not to use ASCII for the character set, but we can see the logic in keeping the number of bits to a minimum and not distracting from the learning process. What’s cool about this is that it engages kids on so many levels. They learn about binary numbers, encoding systems, interfacing a computer to the real world, and if they care to delve deeper, they can learn about the code behind everything. It’s a great hook into the hacking arts.

And once the kids learn a thing or two, maybe they can use this punch-card Twitter interface to tweet their new-found knowledge.


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!

Hacklet 96 – Pi Zero Contest Projects Week 3

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.

tizen[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!

harmNext 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.

retro[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.

brambleFinally 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!

Controlling RGB LEDs With The Pi Zero

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!

Hacklet 94 – Pi Zero Contest Entries

Hackaday and Adafruit have joined forces to present the Raspberry Pi Zero Contest. A great contest is nothing without entries though. This is where the community is proving once again that they’re the best in the world. The contest is less than a week old, yet as of this Thursday evening, we’re already up to 33 entrants! You should submit your own project ideas now for a chance at one of the many prizes. This week on The Hacklet, we’re going to take a look at a few of these early entrants!

controllerWe start with [usedbytes] and Zero Entertainment System [usedbytes] has crammed an entire emulator into a classic Nintendo Entertainment System control pad thanks to the Raspberry Pi Zero. Zero Entertainment System also has something the original NES couldn’t dream of having: An HDMI output. The emulator uses the popular RetroPie front end. We’re happy to say that [usedbytes] knew that hacking up a real Nintendo controller would be sacrilegious, so they grabbed a low-cost USB clone from the far East. A bit of creative parts-stuffing and point-to-point wiring later, ZES was ready to meet the world!

wsprNext up is [Jenny List] with The Australia Project. [Jenny] is a hacker from Europe. She’s hoping to use a Pi Zero to talk to Australia. “Talk” may be pushing it a bit though. The Australia Project will use the Weak Signal Propagation Reporter (WSPR) network to transmit RF straight out of the Pi’s GPIO ports. All that is required is a good filter, an antenna, and a balun. The filter in this case is a 7-pole Chebyshev low-pass filter. The filter keeps the Pi’s harmonic filled square waves from messing up every band from DC to light. [Jenny] normally sells these filters as a kit, but she’s made a special version specifically for the Pi Zero.

tote0[Radomir Dopieralski] has brought his signature walking robots to the Pi Zero world with Tote Zero. Tote Zero is a quadruped walking robot built mainly from 9 gram servos. [Radomir’s] custom tote board interfaces the servos to the Pi Zero itself. The Pi Zero opens all sorts of doors for sensors, vision, and advanced processing. The Arduino board on the original Tote would have been hard pressed to pull that off. Tote is programmed in Python, which will make the code quick and easy to develop. Tote Zero just took its first steps a few days ago, so follow along as a new robot is born!


ethernetpoFinally we have [julien] with PoEPi: Pi Zero Power over Ethernet with PHY. The Raspberry Pi Zero is so tiny, that it’s easy to forget it needs a fair amount of power to run. [Julien] is giving us a way to connect our Pi to a network while ditching the USB power supply using Power Over Ethernet (PoE). PoE has been powering devices like IP cameras for years now. It’s become a standard way of transmitting power and data. For the Ethernet physical interface, [Julien] is using Microchip’s ENC28J60, which has a handy SPI interface. Linux already has drivers in place for the device, so it’s a slam dunk. The “power” part of this system comes with the help of an LTC4267 PoE interface chip, which has a built-in switching regulator.

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 even 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!