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Hackaday Links: February 22, 2015

February 22, 2015 by 24 Comments

We met up with Freescale guy [Witek] at our party in Munich last year, and he wrote in to tell us about the Freescale booth at Embedded World this week in Nuremberg. They’re going to have a bunch of Freedom boards to play around with and an extremely powerful RIoTboard with a 1GHz iMX6 Solo processor, 1GB of RAM, and 4GB of EMMC Flash. It’s not a Raspi or BeagleBone killer, but if you need a small Linux board with a lot of horsepower, there ‘ya go.

SmarterEveryDay is finally getting around to doing a series of videos about space. This guy knows his stuff, and with the access he can get, it should make for interesting viewing.

Here’s something for your Sunday listening: [Vint Cerf] at Carnegie Mellon talking about the Olive Project and the Interplanetary Internet. The Olive project is an archive for executables, and solves the problem of having to preserve hardware along with software. Cool stuff.

10 GHz pulse magnetron destroys electronics. That’s the only information you’re going to get with this one. There’s a fine line between ‘don’t try this at home’ and ‘this project needs replication’.

Most of the northern half of the United States is covered in a billion tons of snow. [Jamie]’s electric snowmobile/Power Wheels is the perfect vehicle for this occasion. It’s 36V with two 500W motors. Figure out how to replace the wheels with small treads, and there’s really something interesting here.

A Smaller, Homebrew Amstrad

February 22, 2015 by 38 Comments

Although they weren’t very popular in America, the Amstrad CPC 464 and CPC 6128 were extremely well-received in Europe. [Zaxon] loved his ‘464, and for a bit of a learning experience – and the fact that an Amstrad takes up an exceptional amount of desk space – decided to make a clone of his favorite computer (.pl, Google translatrix).

The clone began as a simple schematic of the original Amstrad CPC 464, but the parts used in the original required some modern equivalents. Still, most of the old chips remained in the clone; the original Hitachi HD46505 CRT controller remains, as do the original DRAM chips and the vintage Z80 CPU.

A few modern amenities were added, including an interface for a PS/2 keyboard and a disk that’s much improved over the original cassette drive or weird 3.5″ disks: a Disk On Module, or basically a CompactFlash card in a strange form factor that plugs straight into a motherboard’s IDE socket. They’re mostly seen when tearing apart old thin clients, but using them in retrocomputing project is a great idea.

Thanks [rasz_pl] for the tip. Video below.

Continue reading “A Smaller, Homebrew Amstrad” →

MacGyver, Jedi Knights, Ammo Stockpiles, And Candy Crush

February 22, 2015 by 55 Comments

Everyone’s favorite machinist, tinkerer, YouTube celebrity, deadpan comedian, and Canadian is back with a tale of popping a few benzos, stumbling around Mexico, and wondering why everyone else on the planet is so stupid.

The hero of our story considered the feasibility of one hundred and eighty-sixth trimester abortions as he stood outside a Mexican airport watching a stockbroker complain about the battery in his cellphone. Meanwhile, cars drove by.

Here’s how you charge a phone with a car battery and an ‘ol Dixon Ticonderoga.

To charge a battery, all you really need to do is connect the terminals to a power source with the right voltage. A cell phone battery needs about three volts, and a car battery has twelve. You need a voltage divider. You can get that with a pencil. Take out a knife, get to the carbon and clay wrapped in wood, and wire the battery up. Make a cut a quarter of the way down this rather long resistor, and there you will find something around three volts.

Does it work? Yeah. It works even better if you have some tape to hold wires onto the cell phone battery when charging. Is it smart? It is if there is no other conceivable way of charging your cell phone. Should you do it? Nah. Video below. Thanks [Morris] for the link.

Continue reading “MacGyver, Jedi Knights, Ammo Stockpiles, And Candy Crush” →

Toner Transfer And Packing Tape

February 22, 2015 by 41 Comments

The toner transfer process of producing PCBs has evolved tremendously over the last few years. It started out by printing PCB layouts onto magazines with a laser printer, then some clever people figured out that glossy inkjet photo paper would work just as well. Now there’s a new substrate for you – packing tape – and it seems to work pretty well.

[David] was designing a cheap board for a robot kit for a workshop and needed 100 tiny PCBs. They were simple boards, and perfectly suited for home PCB manufacturing. He started off by printing directly onto glossy magazine paper, but this wasn’t an ideal solution. During one run, some of the toner landed on the packaging tape he was using to secure the boards. A bit of serendipity came into play and [David] discovered packaging tape is usable in the toner transfer process.

The technique is simple enough: put some packaging tape on a piece of paper, print a board layout (reversed!) on a laser printer, and go through the usual clothes iron/laminator/etching process. [David] is actually using a hair straightener for transferring the toner over to the copper clad board – interesting, and in a pinch you can use the same tool for reflowing SMD components.

Towards A Reverse Engineering Of Samsung’s S-Pen

February 22, 2015 by 14 Comments

A few years ago, Wacom, the company behind all those cool graphics tablets, teamed up with Samsung to create the S Pen, a rebirth of that weird pen computing thing that happened in the 90s and a very interesting peripheral if only someone would write some software for it. [Kerry D. Wong] was wondering how the S Pen worked and wired up some hardware to take a look at how the pen communicates with the phone.

It was already known that the S Pen was powered by an RF field, and works somewhat like RFID. Listening in on the communication would require a coil of some type, so [Kerry] disassembled a small speaker and connected it to a scope.

A look at the captured waveforms from the S Pen reveled the carrier frequency appears to be in the range of 550 to 560kHz, outside the range of standard RFID. He doesn’t have the equipment to decode the complete protocol, but a few things can be deduced – the screen senses the location of the pen by detecting a dip in the RF field strength. The only information that is transferred between the pen and phone is the 11-bit pressure sensitivity and a 1-bit value that signals the button is on or off.

[Kerry] put the waveform data up on his site should anyone want to make an attempt at decoding the protocol.

RasPi Doorbell

Raspberry Pi Doorbell Is Fully Featured

February 22, 2015 by 37 Comments

When you think of a doorbell, you typically don’t think of anything very complicated. It’s a button that rings a bell inside your home. That’s about it. [Ahmad] decided he wanted to turn his doorbell up to eleven (Google Doc) with this build. Using a Raspberry Pi, he was able to cram in loads of features.

When the doorbell button is pressed, many different events can be triggered. In the demo video, [Ahmad] shows how his phone receives a text message, and email, and a tweet. The system can even be configured to place a voice call via Google Hangouts using a USB microphone. [Ahmad] demonstrates this and shows how the voice call is placed almost instantly when the button is pressed. This may be a bit overkill, but it does demonstrate many different options depending on your own needs.

For the hardware side of things, [Ahmad] purchased a wireless doorbell. He opened up the ringer unit and hooked up the speaker wires to a couple of pins on the Raspberry Pi through a resistor. The doorbell unit itself is powered off of the 3.3V supply from the Pi. The Pi also has a small LCD screen which shows helpful information such as if the Internet connection is working. The screen will also display the last time and date the doorbell was pressed, in case you weren’t home to answer the door.

On top of all of that, the system also includes a Raspberry Pi camera module. This allows [Ahmad] to take a photo of the person ringing the doorbell as a security measure. He can even view a live video feed from the front door by streaming directly to YouTube live. [Ahmad] has provided a link to his Pi image in the Google Doc so others can use it and modify it as they see fit. Continue reading “Raspberry Pi Doorbell Is Fully Featured” →

Store Digital Files For Eons In Silica-Encased DNA

February 21, 2015 by 58 Comments

If there’s one downside to digital storage, it’s the short lifespan.  Despite technology’s best efforts, digital storage beyond 50 years is extremely difficult. [Robert Grass, et al.], researchers from the Swiss Federal Institute of Technology in Zurich, decided to address the issue with DNA.  The same stuff that makes you “You” can also be used to store your entire library, and then some.

As the existence of cancer shows, DNA is not always replicated perfectly. A single mismatch, addition, or omission of a base pair can wreak havoc on an organism. [Grass, et al.] realized that for long-term storage capability, error-correction was necessary. They decided to use Reed-Solomon codes, which have been utilized in error-correction for many storage formats from CDs to QR codes to satellite communication. Starting with uncompressed digital text files of the Swiss Federal Charter from 1291 and the English translation of the Archimedes Palimpsest, they mapped every two bytes to three elements in a Galois field. Each element was then encoded to a specific codon, a triplet of nucleotides. In addition, two levels of redundancy were employed, creating outer- and inner- codes for error recovery. Since long DNA is very difficult to synthesize (and pricier), the final product was 4991 DNA segments of 158 nucleotides each (39 codons plus primers).

Continue reading “Store Digital Files For Eons In Silica-Encased DNA” →