Olimex Announces Their Open Source Laptop

A few months ago at the Hackaday | Belgrade conference, [Tsvetan Usunov], the brains behind Olimex, gave a talk on a project he’s been working on. He’s creating an Open Source Hacker’s Laptop. The impetus for this project came to [Tsvetan] after looking at how many laptops he’s thrown away over the years. Battery capacity degrades, keyboards have a fight with coffee, and manufacturers seem to purposely make laptops hard to repair.

Now, this do it yourself, Open Source Hardware and hacker-friendly laptop is complete. The Olimex TERES I laptop has been built, plastic has been injected into molds, and all the mechanical and electronic CAD files are up on GitHub. This Open Source laptop is done, but you can’t buy it quite yet; for that, we’ll have to wait until Olimex comes back from FOSDEM.

The design of this laptop is completely Open Source. Usually when we hear this phrase, the Open Source part only means the electronics and firmware. Yes, there are exceptions, but the STL files for the PiTop, the ‘3D printable Raspberry Pi laptop’ are not available, rendering the ‘3D printable’ part of PiTop’s marketing splurge incongruent with reality. If you want to build a case for the Open Source laptop to date, [Bunnie]’s Novena, random GitHub repos are the best source. The Olimex TERES I is completely different; not only can you simply buy all the parts for the laptop, the hardware files are going up too. To be fair, this laptop is built with injection molded parts and will probably be extremely difficult to print on a standard desktop filament printer. The effort is there, though, and this laptop can truly be built from source.

As far as specs go, this should be a fairly capable laptop. The core PCB is built around an Allwinner ARM Cortex-A53, sporting 1GB of DDR3L RAM, 4GB of eMMC Flash, WiFi, Bluetooth, a camera, and an 11.6″ 1366×768 display. Compared to an off-the-shelf, bargain-basement consumer craptop, those aren’t great specs, but at least the price is consummate with performance: The TERES I will sell for only €225, or about $250 USD. That’s almost impulse buy territory, and we can’t wait to get our hands on one.

Filed under: computer hacks, laptops hacks

// from Hackaday http://ift.tt/2kaMbO9
site=blogger">IFTTT

Building A Wavetable Synth

Every semester at one of [Bruce Land]’s electronics labs at Cornell, students team up, and pitch a few ideas on what they’d like to build for the final project. Invariably, the students will pick what they think is cool. The only thing we know about [Ian], [Joval] and [Balazs] is that one of them is a synth head. How do we know this? They built a programmable, sequenced, wavetable synthesizer for their final project in ECE4760.

First things first — what’s a wavetable synthesizer? It’s not adding, subtracting, and modulating sine, triangle, and square waves. That, we assume, is the domain of the analog senior lab. A wavetable synth isn’t a deep application of a weird reverse FFT — that’s FM synthesis. Wavetable synthesis is simply playing a single waveform — one arbitrary wave — at different speeds. It was popular in the 80s and 90s, so it makes for a great application of modern microcontrollers.

The difficult part of the build was, of course, getting waveforms out of a microcontroller, mixing them, and modulating them. This is a lab course, so a few of the techniques learned earlier in the semester when playing with DTMF tones came in very useful. The microcontroller used in the project is a PIC32, and does all the arithmetic in 32-bit fixed point. Even though the final audio output is at 12-bit resolution, the difference between doing the math at 16-bit and 32-bit was obvious.

A synthesizer isn’t useful unless it has a user interface of some kind, and for this the guys turned to a small TFT display, a few pots, and a couple of buttons. This is a complete GUI to set all the parameters, waveforms, tempo, and notes played by the sequencer. From the video of the project (below), this thing sounds pretty good for a machine that generates bleeps and bloops.

Filed under: musical hacks

// from Hackaday http://ift.tt/2l7yaVE
site=blogger">IFTTT

DIY Wire Spooler with Clever Auto-Tensioning System

[Solarbotics] have shared a video of their DIY wire spooler that uses OpenBeam hardware plus some 3D printed parts to flawlessly spool wire regardless of spool size mismatches. Getting wire from one spool to another can be trickier than it sounds, especially when one spool is physically larger than the other. This is because consistently moving wire between different sizes of spools requires that they turn at different rates. On top of that, the ideal rate changes as one spool is emptying and the other gets larger. The wire must be kept taut when moving from one spool to the next; any slack is asking for winding problems. At the same time, the wire shouldn’t be so taut as to put unnecessary stress on it or the motor on the other end.

There aren’t any build details but the video embedded below gives a good overview and understanding of the whole system. In the center is a tension bar with pulleys on both ends though which the wire feeds. This bar pivots at the center and takes up slack while its position is encoded by turning a pot via a 3D printed gear. Both spools are motor driven and the speed of the source spool is controlled by the position of the tension bar. As a result, the bar automatically takes up any slack while dynamically slowing or speeding the feed rate to match whatever is needed.

There’s nothing like facing down a repetitive and lengthy task to get a good solution brewing. This reminds us of another DIY automation solution to a wire-related need: a contraption to cut 1,000 pieces of wire.

Filed under: tool hacks

// from Hackaday http://ift.tt/2lbWnae
site=blogger">IFTTT

Up to 25% off Amazon Kindle and Fire Tablets - Deal Alert

Up to 25% off Amazon Kindle and Fire Tablets - Deal Alert

Grant Anyone Temporary Permissions to Your Computer with SSH

This is a super cute hack for you Linux users out there. If you have played around with SSH, you know it’s the most amazing thing since sliced bread. For tunneling in, tunneling out, or even just to open up a shell safely, it’s the bees knees. If you work on multiple computers, do you know about ssh-copy-id? We had been using SSH for years before stumbling on that winner.

Anyway, [Felipe Lavratti]’s ssh-allow-friend script is simplicity itself, but the feature it adds is easily worth the cost of admission. All it does is look up your friend’s public key (at the moment only from GitHub) and add it temporarily to your authorized_keys file. When you hit ctrl-C to quit the script, it removes the keys. As long as your friend has the secret key that corresponds to the public key, he or she will be able to log in as your user account.

There’s really nothing going on here that you couldn’t do by hand. The script simply automates creating and removing the public key, and uses GitHub as an arbiter of your friend’s identity. If you know their GitHub user name for sure, and they have attached their public key to the account, this is a very streamlined and simple procedure. (We tried it out ourselves, only to find that we hadn’t associated a public SSH key with our account.) That said, it can be extended to any trusted location that serves up public keys.

Looking through our musty archives for an article on SSH tips and tricks, we couldn’t find one. Is that possible, commenteers? That’s something we’ll have to get right on top of so send us your favorite SSH magic. In the mean time, we’ll placate your lust for more Hackaday by tossing up [Al Williams]’s nice writeup of MOSH, a mobile SSH client.

Filed under: internet hacks, linux hacks

// from Hackaday http://ift.tt/2lbqKwy
site=blogger">IFTTT

Two Guitars, Two Amps, And Three Pole Dual Throw

[Alexbergsland] plays electric guitar. More accurately, he plays two electric guitars, through two amps. Not wanting to plug and unplug guitars from amps and amps from guitars, he designed an AB/XY pedal to select between two different guitars or two different amps with the press of a button.

The usual way of sending a guitar signal to one amp or another is with an A/B pedal that takes one input and switches the output to one jack or another. Similarly, to switch between two inputs, a guitarist would use an A/B pedal. For [Alex]’ application, that’s two pedals that usually sell for $50, and would consequently take up far too much room on a pedalboard. This problem can be solved with a pair of 3PDT footswitches that sell for about $4 each. Add in a few jacks, LEDs, and a nice aluminum enclosure, and [Alex] has something very cool on his hands.

The circuit for this switcher is fairly simple, so long as you can wrap your head around how these footswitches are wired internally. The only other special addition to this build are a trio of LEDs to indicate which output is selected and if both inputs are on. These LEDs are powered by a 9V adapter embedded in the pedalboard, but they’re not really necessary for complete operation of this input and output switcher. The LEDs in this project can be omitted, making this a completely passive pedal to direct signals around guitars and amps.

Filed under: musical hacks

// from Hackaday http://ift.tt/2kG9eDJ
site=blogger">IFTTT