Cheap USB Control for your Telescope

There’s many complex systems for automatically pointing a telescope at an object in the sky, but most of them are too expensive for the amateur astronomer. [Kevin]’s Arduino ST4 interface lets you connect your PC to a reasonably priced motorized telescope mount, without ripping it apart.

The ST4 port is a very basic interface. There’s one pin per direction that the mount can move, and a common pin. This port can be added to just about any motorized mount with some modification to the controller. To connect to an Arduino, a TLP521-4 quad optoisolator is used. This keeps the Arduino and PC fully isolated from the motor circuits. but lets the Arduino take control of the mount.

With the hardware in place, [Kevin] cranked out some software which is available on Google Code. A simple Arduino sketch provides the USB interface, and a custom driver allows the ASCOM Platform to control the mount. Since many astronomy software tools support ASCOM, this allows the mount to be controlled by existing software.

With the interface in place, the mount can be used to find objects (GOTO) and automatically follow them with high accuracy (autoguiding). You can watch the telescope move on its own after the break.

Continue reading “Cheap USB Control for your Telescope”

DIY USB Stereo Headphone Amplifier

The biggest and best audiophile projects are usually huge tube amps, monstrous speaker cab builds, or something else equally impressive. It doesn’t always have to be that way, though, as [lowderd] demonstrates with a tiny DIY USB DAC build that turns a USB port into a headphone output.

In the Bad Old Days™ putting a DAC on a USB bus would require some rather fancy hardware and a good amount of skill. These days, you can just buy a single chip USB stereo DAC that still has very good specs. [lowderd] used the TI PCM2707 USB DAC, a chip that identifies as a USB Audio Class 1.0 device, so no drivers are needed for it to work in either Windows or OS X.

The circuit fits on a tiny PCB with a USB port on one side, a headphone jack on the other, and the chip and all related components in between. There are some pins on the chip that allow for volume, play/pause. and skip, but these pins were left unconnected for sake of simplicity.

The board was fabbed up at OSH Park, and the second revision of the case laser cut out of bamboo and acrylic by Ponoko. It’s a great looking little box, and something that fits right inside [lowderd]’s headphone case.

Husband Uses MRI images to 3D print Wife’s Skull and Tumor

[Michael Balzer] shows us that you are your own best advocate when it comes to medical care – having the ability to print models of your own tumors is a bonus. [Michael’s] wife, Pamela, had been recovering from a thyroidectomy when she started getting headaches. She sought a second opinion after the first radiologist dismissed the MRI scans of her head – and learned she had a 3 cm tumor, a meningioma, behind her left eye.  [Michael], host of All Things 3D, asked for the DICOM files (standard medical image format) from her MRI.  When Pamela went for a follow-up, it looked like the tumor had grown aggressively; this was a false alarm. When [Michael] compared the two sets of DICOM images in Photoshop, the second MRI did not truly show the tumor had grown. It had only looked that way because the radiologist had taken the scan at a different angle! Needless to say, the couple was not pleased with this misdiagnosis.

However, the meningioma was still causing serious problems for Pamela. She was at risk of losing her sight, so she started researching the surgery required to remove the tumor. The most common surgery is a craniotomy: the skull is sawed open and the brain physically lifted in order to access the tumor below it. Not surprisingly, this carries a high risk of permanent damage to any nerves leading to loss of smell, taste, or sight if the brain is moved the wrong way. Pamela decided to look for an alternative surgery that was less invasive. [Michael] created a 3D print of her skull and meningioma from her MRIs. He used InVesalius, free software designed to convert the 2D DICOM files into 3D images. He then uploaded the 3D rendered skull to Sketchfab, sharing it with potential neurologists. Once a neurologist was found that was willing to consider an alternative surgery, [Michael] printed the skull and sent it to the doctor. The print was integral in planning out the novel procedure, in which a micro drill was inserted through the left eyelid to access the tumor. In the end, 95% of the tumor was removed with minimal scarring, and her eyesight was spared.

If you want to print your own MRI or CT scans, whether for medical use or to make a cool mug with your own mug, there are quite a few programs out there that can help. Besides the aforementioned InVesalius, there is DeVIDE, Seg3D, ImageVis3D, and MeshLab or MeshMixer.

[via Make]

New Part Day: Three-dimensional USB Connectors

There’s an old joke that says USB cables do not exist in three-dimensional Euclidian space. Try to plug a USB cable in a socket, and the first try will always be wrong. Flip it, try to plug it in, and that will also be wrong. You will only succeed on the third try, and this is proof that USB connectors exist in higher planes of reality with arcane geometries. The joke is as old as the Pythagoreans, who venerated USB connectors as gods.

The waveform has collapsed, the gods profaned, and USB connectors that exist in only three dimensions have arrived. We’re talking, of course, about reversible USB Type A connector that will plug in the first time, every time. No need for electromancy or the “looking on the cable for the USB logo and plugging it in with that side up” method used by tech plebeians.

This discovery came after going through my daily roundup of crowdfunding press releases, eventually landing me on this idiotic project. It’s a USB charge cable that’s supposed to charge your phone twice as fast, despite the fact that charging speed is a function of current, and that’s determined by whatever you’re charging from, not the cable. Terrible idea, but they do have something interesting: a three-dimensional USB connector.

connUSBThe connector isn’t the brand new USB 3.1 Type C connector that will eventually find its way into phones, laptops, wearables of all types. This is your standard Type A USB plug you’ve known and loved for the past eighteen years. The difference here is that the chunky block of plastic that has made the common USB cable non-reversible for so many years is gone. In its place is a tiny strip of plastic that has contacts on both sides. Yes, it took nearly two decades for someone to figure out this would be a marketable idea.

While searching for a source for these three-dimensional USB connectors, the only source I could come up with was Wurth Elektronik, With Farnell/Element14 carrying a selection of connectors, a few available on Digikey, and some available on Mouser. There are even a few pre-made reversible cables available, with Tripp Lite leading the game right now.

For integrating one of these connectors into your build, there’s only one thing to watch out for: the pinout for these plugs is mirrored on each side of the thin strip of plastic going down the middle of the connector. This means your VCC and GND pins will be right next to each other, your D+ and D- signal pins right next to each other, and now you have to do your layout with eight pins instead of only four.

While it may not be groundbreaking and it makes for some confusing PCB layout work, but as told by a highly successful crowdfunding campaign, this can be a real feature for a product.

If you’ve recently come across a component, connector, or part that’s unique, interesting, or downright cool everyone should know about, send it on in and we’ll take a look at it.

Never Forget Your USB Stick Again

USB sticks are very handy. They are a very portable and relatively inexpensive means of storing data. Possibly the most annoying part about using one of these devices is when you inevitable leave it behind somewhere by accident. This is especially true if it contains sensitive information. [Eurekaguy] feels your pain, and he’s developed a solution to the problem.

[Eurekaguy] designed a custom cap for USB sticks that beeps approximately every minute after the USB stick has been plugged in for five minutes. The cap is 3D printed and then slightly modified with four 1mm holes. Two wires are routed between these holes to make contact points for the VCC and GND pins of the USB stick.

The beep circuit is comprised of a tiny PIC12F629 microcontroller along with a couple of other supporting components. The circuit is wired together dead bug style to conserve space. Three AG5 batteries power the circuit. A small piezo speaker provides the repeating beep to remind you to grab your USB stick before you walk away from the computer.

[Thanks Irish]

Trinket EDC Contest: USB Calipers

[Lou]’s entry for the Trinket EDC Contest is a great addition to the ubiquitous digital calipers found on workbenches and eBay resellers the world over. It translates the value displayed on the calipers to a USB HID interface for logging all those tricky measurements at the push of a button.

Most of the digital calipers you’ll find at Harbor Freight or on eBay are pretty much the same. There are two pads on the caliper’s PCB that give any microcontroller the ability to read what is being measured. It’s done with a 24-bit encoding scheme, where each bit is a nearly-BCD measurement in units of 1/1000 of an inch or 1/100 of a millimeter. After decoding the value, [Lou]’s trinket sends a few numbers to a computer over a USB HID interface.

Simply sending a measurement to a computer over USB wasn’t enough for [Lou]. He added three buttons to the project for typing multiple characters. The first button just sends Enter to the computer, the second sends a comma, and the third sends “/2 (Enter)”, exactly what you need to input the radius of something when measuring the diameter.

This was a project for the Trinket EDC Contest that ended a few hours ago. Nobody knows who the winner is, but there are some pretty cool prizes up for grabs including the new Rigol scope, a Fluke 179, and a soldering station.

Game Boy with Lithium Batteries and USB

[Alan] procured a few Game Boys from a Yahoo auction with the intent of using them for some other projects, but one of the Game Boys was shipped with a very corroded battery which had eaten up one of the terminals. When [Alan] had repaired it, he was left with a Game Boy with no battery terminal at all, so he decided to splice in some lithium-ion batteries.

Not only does the Game Boy now have a new battery pack, but [Alan] was able to source a USB charger to handle the batteries’ charging needs. However, he realized that his battery pack was 3.7 volts, while the Game Boy only needed 3 volts. To lower the voltage of the battery pack to the required voltage, [Alan] grabbed a 1N4148 diode and put it in series with the battery pack, which also helps prevent any accidental reverse polarity.

This isn’t the most technically advanced Game Boy hack we’ve ever seen but it’s great to see new life breathed into these classic video game systems. Not to mention that [Alan] saved some lithium batteries from the landfill!