Pi Zero Gives Telescope Hands Free Focus

February 12, 2018 by Tom Nardi 7 Comments

It seems like [Jason Bowling] never gets tired of finding new ways to combine the Raspberry Pi with his love of the cosmos. This time he’s come up with a very straightforward way of focusing his Celestron 127SLT with everyone’s favorite Linux SBC. He found the focus mechanism on the scope to be a bit fiddly, and operating it by hand was becoming a chore. With the Pi Zero and a stepper motor, he’s now able to focus the telescope with more accuracy and repeatability than clumsy human fingers will be able to replicate.

On this particular type of telescope, the focus knob is a small knob on the back of the scope (rather than on the eyepiece), which just so happens to be the perfect size to slide a 15mm bore pulley over. With a pulley on the focus knob, he just needed to mount a stepper motor with matching toothed pulley next to it and find a small enough belt to link them together. Through the magic of Amazon and McMaster-Carr he was able to find all the parts without having to make anything himself, beyond the bent piece of aluminum he’s using as a stepper mount.

To control the stepper, [Jason] is using an EasyDriver connected up to the Pi’s GPIO, which along with a 5V regulator (which appears to be a UBEC from the RC world) is held in a tidy weather proof box mounted to the telescope’s tripod. The regulator is necessary because the whole setup is powered by a 12V portable “jump start” battery pack for portability. Handy when you’re stargazing in the middle of a field somewhere.

[Jason] promises a future blog post where he details how he used Flask to create a web-based control for the hardware, which we’ll be keeping an eye out for. In the meantime, he reports that his automated focus system is working perfectly and keeps the image stable in the eyepiece even while moving (something he was never able to do by hand).

Last year this same scope had a Raspberry Pi camera mounted to it to deliver some very impressive pictures without breaking the bank. We’re interested in seeing how [Jason] ties these systems together going forward.

Plastic Model Emulates The First Untethered Spacewalk

February 11, 2018 by Donald Papp 18 Comments

Here’s something really wonderful. [Dave Akerman] wrote up the results of his attempt to use a high-altitude balloon to try to re-create a famous image of NASA’s Bruce McCandless floating freely in space with the Earth in the background. [Dave] did this in celebration of the 34th anniversary of the first untethered spacewalk, even going so far as to launch on the same day as the original event in 1984. He had excellent results, with plenty of video and images recorded by his payload.

Adhering to the actual day of the spacewalk wasn’t the only hurdle [Dave] jumped to make this happen. He tracked down an old and rare “Astronaut with MMU” (Mobile Maneuvering Unit) plastic model kit made by Revell USA and proceeded to build it and arrange for it to remain in view of the cameras. Raspberry Pi Zero Ws with cameras, LoRA hardware, action cameras, and a UBlox GPS unit all make an appearance in the balloon’s payload.

Sadly, [Bruce McCandless] passed away in late 2017, but this project is a wonderful reminder of that first untethered spacewalk. Details on the build and the payload, as well as the tracking system, are covered here on [Dave]’s blog. Videos of the launch and the inevitable balloon burst are embedded below, but more is available in the summary write-up.

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Careful Testing Reveals USB Cable Duds

February 2, 2018 by Dan Maloney 29 Comments

What’s worse than powering up your latest build for the first time only to have absolutely nothing happen? OK, maybe it’s not as bad as releasing the Magic Smoke, but it’s still pretty bewildering to have none of your blinky lights blink like they’re supposed to.

What you do at that point is largely a matter of your troubleshooting style, and when [Scott M. Baker]’s Raspberry Pi jukebox build failed to chooch, he returned to first principles and checked the power cable. That turned out to be the culprit, but instead of giving up there, he did a thorough series of load tests on multiple USB cables to see which ones were suspect, with interesting results.

[Scott] originally used a cable with a USB-A on one end and a 3.5-mm barrel plug on the other with a switch in between, under the assumption that the plug on the Pi end would be more robust, as well as to have a power switch for the jukebox. Testing that cable using an adjustable DC load would prove that the cable was unfit for Pi duty, dropping the voltage to under 2 volts at a measly 500-mA load. Other cables proved much better under load, even those with USB mini jacks and even one with a 5.5-mm barrel. But the larger barrel-plug cable also proved to be a stinker when it was paired with an inline switch. In the video below, [Scott] walks through not only the testing process, but also gives a quick tour of his homebrew DC load.

The lesson is clear: not all USB cables are created equal, so caveat hacker. And if you’ve got a yen to check the cables in your junk bin like [Scott] did, this full-featured smart DC load might be just the thing.

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A Grandfather Clock BarBot

February 1, 2018 by James Hobson 10 Comments

As the saying goes, it’s five o’clock somewhere; when the clock finally strikes the hour, that same clock can pour you a drink thanks to redditor [Diggedypomme].

This bar-clock can dispense beverages with up to four different spirits and four mixers, and takes orders over voice, keyboard, or web-controls. A belt-driven drink loading platform pushes out through a spring-loaded door and once the vessel is in place and the order received, peristaltic pumps dispense the spirits while servos open taps for the mixers — a far easier method to administer the often carbonated liquids. A Raspberry Pi acts as this old-timer’s brain, an Arduino controls the lights, and a HAT to controls the servos. Here’s a more in-depth tour of what’s going on behind the bar, but check out the video after the break for a full run through of a few drink orders!

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Putting The Pi In Piano

January 31, 2018 by James Hobson 10 Comments

Working on a PhD in composition, [Stephen Coyle] spends a fair bit of time at his electric keyboard. Setting himself up to work can be a bit of a task, so he felt he could improve the process and make it easy as Pi.

Finding it an odious task indeed to use notation software, connecting his laptop to his keyboard is a must — avoiding a warren of wires in the move is a similar priority. And, what if he could take advantage of the iPad’s unique offerings too? Well, a Raspberry Pi Zero W running Ravelox — an RTP MIDI protocol — makes his music available on his network to record on whichever device he pleases.

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More Than Just An Atari Look-Alike

January 28, 2018 by James Hobson 4 Comments

The Raspberry Pi has been a boon for hackers with a penchant for retro gaming. Redditor [KaptinBadkruk] Wanted to get on board the game train and so built himself an Atari 2600-inspired Raspberry Pi 3 console!

A key goal was the option to play Nintendo 64 titles, so [KaptinBadkruk] had to overclock the Pi and then implement a cooling system. A heatsink, some copper pads, and a fan from an old 3D printer — all secured by a 3D printed mount — worked perfectly after giving the heatsink a quick trim. An old speaker and a mono amp from Adafruit — and a few snags later — had the sound set up, with the official RPi touchscreen as a display.

After settling on an Atari 2600-inspired look, [KaptinBadkruk] laboured through a few more obstacles in finishing it off — namely, power. He originally intended for this project to be portable, but power issues meant that idea had to be sidelined until the next version. However — that is arguably offset by [KaptinBadkruk]’s favourite part: a slick 3D Printed item box from Mario Kart front and center completes the visual styling in an appropriately old-meets-new way.

That item block isn’t the first time a lightshow has accompanied an Atari console, but don’t let that stop you from sticking one in your pocket.

[Via /r/DIY]

A New Life For A Dead VIC-20

January 26, 2018 by Kristina Panos 23 Comments

What was the first computer you bent to your programmatic will? If you’re old enough, it was probably a Commodore. For [Jagged-path], it was a VIC-20. After finding a broken one on Kijiji, he recaptured that 80s feeling with VicPi, a revitalization project that marries modern computing power with vintage form factor.

The VicPi can be used as a standalone computer or a USB keyboard for an external computer. As you’ve probably guessed, there’s a Raspberry Pi involved. There is also a Keyrah board, which is arguably the easiest way to convert Commodore (and Amiga) keystrokes to USB without breaking a sweat.

There are a lot of nice touches that really make this project. A toggle switch on the back selects between VicPi mode and keyboard mode, and the distinction is made with a two-color LED in place of the VIC-20’s power LED. [Jagged-path] used panel mount cables to extend the HDMI, 3.5mm, and USB ports and ran them out to a custom metal panel that’s treated with rubberized black paint. Another nice touch: the dedicated keyboard port is USB-B, so it’s easy to differentiate from the Pi inputs.

If you have a working VIC-20 but not the rare Votrax Type ‘n Talk synthesizer peripheral, you can use an old Android phone to hear those Voodoo Castle responses.