Homemade 3D Carving Duplicator

April 11, 2015 by Rich Bremer 8 Comments

[Frank] is a guitar builder and has to make a quantity of acoustic guitar bridges that wouldn’t make sense to do manually by hand each time. He wanted a way of duplicating bridges quickly and precisely but he didn’t want to go to a CNC machine. Instead, he build a 3D duplicating machine.

The machine has 3 perpendicular axes, just like a milling machine. Mounted to the Z Axis is an air powered spindle that can reach 40,000 RPM. All 3 axes are moved by the operators hands. Normally, free-hand cutting something like this would be very difficult. [Frank’s] solved this in his machine by using a stylus that is offset from the cutting bit. The stylus is the same effective length and diameter of the cutting bit and is guided over a finished bridge pattern. While the stylus is tracing the pattern, the spindle and bit are removing material from a bridge blank. The stylus is continually moved over the entire pattern bridge until the spindle is finished carving out a new bridge out of the blank.

To aid in lifting the heavy Z Axis and spindle, [Frank] added a counter balance to make tracing the pattern extremely easy. Once the new bridge is carved, it only requires minor sanding to remove the tool marks before being installed on a guitar! [Frank] admits his linear bearings and rails are very rigid but also very expensive. If you’re interested in a less-expensive 3D duplicator, check out this project.

A VU-meter Indicator For A Commodore 1530 Datasette

April 11, 2015 by Anool Mahidharia 9 Comments

For present-day owners of vintage Commodore computers, keeping data and programs safe and backed up is top priority. Disk drive storage was more common in the US, whereas in Europe, the audio cassette was the preferred medium of storage.

The Datasette device was what allowed interfacing the cassettes to the computer. Tape head alignment was critical to successfully writing and reading data to the cassette. Some models of the Datasette came with a small hole above the keys, to allow access to the adjustment screw of the tape head azimuth position. Tweaking this while looking at a signal meter could help you improve the signal from a bad cassette and prevent load errors. [Jani] tried a commercial solution called “Load-IT” which had a LED bargraph, but it couldn’t help much dealing with tapes with very bad signals. So he built a signal strength meter for his Datasette. He calls it the VU-sette since it uses an analog style meter quite similar to the VU-meters found in many audio equipment.

The hardware is simple and uses commonly available parts. The analog meter is extracted from a Battery Checker sourced from eBay. An op-amp drives the analog meter, and another transistor drives a separate speaker. This can be used to listen in on the cassette, if the speaker is enabled via a push button. [Jani] first breadboarded and tested the circuit before ordering out prototype boards.

To test performance, [Jani] used FinalTAP, a tool for examining, cleaning and restoring digitized data cassette tapes (TAP files) for the Commodore 64 computer. The “LOAD-IT” version worked well with tapes that were in fairly good condition. But his VU-sette version allowed him to adjust the head more precisely and get out a much better read from bad tapes. While on the subject, check out this nice 7-segment bubble LED digital counter for the 1530.

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Overengineering Beer Pong

April 11, 2015 by Brian Benchoff 15 Comments

If there’s one game that deserves to be overengineered with hundreds of LEDs, sensors, and electronic modules, it’s beer pong. [Jeff] has created the most ostentatious beer pong table we’ve ever seen. It’s just shy of playing beer pong on a single gigantic LED display, and boy, does it look good.

The table includes a 32×12 grid of LEDs in the center of the table, with 10 pods for Solo cups at each end of the table. These pods have 20 RGB LEDs each and infrared sensors that react to a cup being placed on them. The outer edge of the table has 12 LED rings for spectators, giving this beer pong table 1122 total LEDs on 608 individual channels.

With that many LEDs, how to drive all of them becomes very important. There’s a very large custom board in this table with a PIC24 microcontroller, TLC5955 PWM drivers, and enough IDC headers to seriously reconsider using IDC headers.

Put enough LEDs on something and it’s bound to be cool, but [Jeff] is taking this several steps further with some interesting features. There’s a Bluetooth module for controlling the table with a phone, a VU meter to give the table some audio-based visualizations, and air baths for cleaning the balls; drop a ball down the ‘in’ hole, and it pops out the ‘out’ hole, good as new. If you’ve ever wondered how much effort can go into building a beer pong table, there you go. Video below.

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Reverse Engineering Galaga To Fix The No-Fire Cheat

April 11, 2015 by Elliot Williams 13 Comments

We didn’t know there was a cheat to Galaga, but [Chris Cantrell] did. And so he did what any curious hacker would do — reverse-engineer the game to diagnose and eventually fix the bug.

Spoilers ahoy! Go read the website first if you’d like to follow [Chris]’s reversing efforts in the order that they actually happened.

The glitch is triggered by first killing most of the bees. When only six are left, they go into a second pattern where they swoop across the screen and wrap around the edges. While swooping, sometimes the bees will fire a shot when they’re at coordinates with X=0. Now two facts: there’s a maximum of eight missiles on the screen at any given time, and the position X=0 was reserved by the software to hide sprites that don’t need updating.

The end result is that eight missiles get stuck in a place where they never drop and don’t get drawn. No further shots are fired in the entire game. You win.

So that’s the punchline, but everyone knows that a good joke is in the telling. If you’re at all interested in learning reverse engineering, go read [Chris]’s explanations and work through them on your own.

And here’s our generic plug for Computer Archaeology:

Ancient video games run on MAME or similar emulators are the perfect playground for learning to reverse engineer; you can pause the machine, flip a bit in memory, and watch what happens next. Memory was expensive back then too, so the games themselves are small. (It’s not like trying to reverse engineer all however many jiggabytes of Microsoft Office.) The assembly languages for the old chips are small and well-documented, and most of the time you’ve also got a good dissasembler. What more could you ask for?

A walkthrough tutorial? We’ve just given you one.

Oh and PS: If you get past level 255, the game freaks out.

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Building A Pinball Emulator

April 11, 2015 by Brian Benchoff 21 Comments

Building a MAME machine – an arcade cabinet that will play everything from Galaga to Street Fighter II – is surely on the ‘to build’ list of thousands of Hackaday readers around the world. It’s a relatively simple build, provided you can put a sheet of MDF in your car; it’s just an emulator, and if you can find a CRT and have an old computer sitting around, you’re already halfway there.

There is another class of arcade games that can be emulated. This is, of course, pinball machines. [Jan] built a virtual pinball cabinet over the last few months and his build log is incredible. If you’ve ever wanted to build a pinball emulator, this is the guide to reference.

The most important part of a pinball emulator is the displays. For this, [Jan] is using a 40-inch TV for the playfield, a 28-inch monitor to display the backglass art, and a traditional 128×32 DMD. Instead of manufacturing his own cabinet, he repurposed an old electromechanical machine, Bally’s Little Joe.

The software is the real star of the show with PinballX serving as the front end, with Future Pinball and Visual Pinball serving as the emulators. These emulators drive the displays, changing out back glasses, and simulating the physics of the ball. The computer running all of this has a few neat electromechanical bits including a shaker motor, an original Williams replay knocker, and some relays or solenoids give the digital table a tremendous amount of force feedback. This is the way to do it, and if you don’t have these electromechanical bits and bobs securely fastened to the machine, you really lose immersion.

You can check out a video of the table in action below.

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Raspberry Pi Controlled Chicken Door

April 11, 2015 by Anool Mahidharia 18 Comments

We’re not sure if the Chickens know it yet, but they could be one of the reasons for all this IoT craze now a days. Look for chicken coop, and out come dozens of posts from the Hackaday chest.

Here’s another one from self confessed lazy engineer [Eric]. He didn’t want to wake up early to let his chickens out in the morning, or walk out to the coop to lock them up for the night to protect them from predators like Foxes, Raccoons and Opossum. So he built a Raspberry-Pi controlled chicken coop door that automates locking and unlocking. The details are clear from his video which you can watch after the break. The door mechanism looks inspired from an earlier anti-Raccoon gravity assist door.

The hardware (jpg image) is simple – a couple of hall sensors that detect the open/close status of the coop door that is driven by a DC motor via a bridge controller. The whole setup is controlled using a Raspberry-Pi and this is where the fun starts – because he can now add in all kinds of “feature creep”. Motion sensor, camera, light array, and anti-predator gizmos are all on his drawing board at the moment. Add in your feature requests in the comments below and let’s see if [Eric] can build the most advanced, complicated, gizmo filled chicken coop in the Universe. Combine that with this design, and it could even turn out to be the most beautiful too.

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Automated Weatherproof Timelapse System With DSLR And Raspberry Pi

April 10, 2015 by Bryan Cockfield 5 Comments

[madis] has been working on time lapse rigs for a while now, and has gotten to the point where he has very specific requirements to fill that can’t be done with just any hardware. Recently, he was asked to take time lapse footage of a construction site and, due to the specifics of this project, used a Raspberry Pi and a DSLR camera to take high quality time lapse photography of a construction site during very specific times.

One of his earlier rigs involved using a GoPro, but he found that while the weatherproofing built into the camera was nice, the picture quality wasn’t very good and the GoPro had a wide-angle lens that wouldn’t suit him for this project. Luckily he had a DSLR sitting around, so he was able to wire it up to a Raspberry Pi and put it all into a weatherproof case.

Once the Pi was outfitted with a 3G modem, [madis] can log in and change the camera settings from anywhere. It’s normally set up to take a picture once every fifteen minutes, but ONLY during working hours. Presumably this saves a bunch of video editing later whereas a normal timelapse camera would require cutting out a bunch of nights and weekends.

The project is very well constructed as well, and [madis] goes into great detail on his project site about how he was able to build everything and configure the software, and even goes as far as to linking to the sites that helped him figure out how to do everything. If you’ve ever wanted to build a time lapse rig, this is probably the guide to follow. It might even be a good start for building a year-long time lapse video. If you want to take it a step further and add motion to it, check out this time lapse motion rig too!