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The Hackaday Store has been up and running for a year and a half now, sending out Hackaday Omnibus, t-shirts, [Alex Rich]’s Stickvice, and an entire MeArm-y from [Phenoptix]. After eighteen months, the enslaved robots in the warehouse are plotting a rebellion, so we’re stamping that right out with a Spring sale in the Hackaday Store!
Shipping is free on US orders over $35, Canadian orders over $50, and International orders over $75 (Unfortunately we’re unable to ship to all countries right now). Sale items are at clearance prices and are final sale. We will only exchange if the item is faulty (if the item is no longer available you will be given store credit).
Buying the CRT Android tee will make you more popular. Consume.
Dallas Texas played host to an epic Hackaday meetup last weekend. The Dallas Makerspace was kind enough to open their doors, and we sure used them. Attendance was over capacity, with a line all night to screen-print your own T-shirt, a set of lightning talks that lasted nearly two hours, and plenty of hardware show-and-tell.
We’ll start off with three of the most impressive builds displayed. First is a set of simple designs that can be used to make tools in parts of the world where even a hammer is a luxury. Then it’s on to a clever entertainment device that uses discrete stopped-motion figurines to make live animations. We’ll take a look at the Witch-E project which is building a replica of the famous Dekatron-based computer. And finish up with the surprise hit of the meetup.
There’s something about pinball that draws in hackers, makers, and engineers. Maybe it’s the flashing lights, the sounds, the complex mechanical movements. Could it be the subtle tactics required to master the game? Whatever the reason, everyone loves pinball, and more than a few hackers have dedicated their time and money toward building, restoring, and hacking pinball machines. This week’s Hacklet is all about the best pinball projects on Hackaday.io!
We start with [zittware] and Star Trek: The Mirror Universe Pinball. [Zittware] worked with [clay], [fc2sw], and [steve] to create this awesome project. They took a 1978 Bally Star Trek pinball machine, and rebuilt an evil mirror universe version. The electronics include nixie tubes and a bulletproof power supply based upon an ATX computer setup. New play field elements and hardware were created on a CNC. Evil graphics were created with the help of Photoshop. The game is completely playable, and was a crowd favorite in the Hackaday Sci-Fi contest. The electronics and cabinet work are all open source. Unfortunately those pesky copyright laws prevent the team from sharing the artwork.
Next up is [Erland Lewin] with RINNIG Pinball Simulator. Some hackers have the space for a few real pinball machines. For the rest of us, there is virtual pinball. [Erland Lewin] built this mini virtual pinball machine from plywood, some real pinball hardware, and a lot of ingenuity. The play field is a 24″ dell computer monitor, while the back glass is a 20″ monitor. A final 15″ monitor takes the place of the Dot Matrix Display (DMD) often found on pinball machines. The whole system is driven by an Intel i3 computer. [Erland] is going to try to use the on-board graphics. If he runs into trouble, he can always switch to a discrete graphics card. The machine has turned out great, and his sons love playing classic pinball machines on their own “kid sized” table.
If virtual pinball is still a bit large for you, [Loyal J] has you covered with Pinbox Jr. Desktop computer virtual pinball has been a thing since the days of Windows XP. Somehow tapping keyboard keys isn’t quite the same as hitting real flipper buttons. Pinbox Jr. is a prototype pinball controller built inside a cardboard box. A Teensy 3.1 translates the buttons to USB keyboard inputs. Two large arcade buttons act as the flippers while two smaller buttons are available for game options and other functions. [Loyal J] even added a triple axis accelerometer so pinbox responds to rough play with a tilt! All this project needs is a solenoid to replicate that real pinball feel.
At the top of the virtual pinball mountain stands [Randy Walker] with Optimus-Pin. Optimus is a full-sized virtual pinball cabinet. It’s a 3 screen affair, much like RINNIG Pinball up top. [Randy] took things to the next level with an absolutely gorgeous custom cabinet. The Transformers inspired artwork was created on commission by commercial artist [Javier Reyes]. Optimus really recreates the feel of playing pinball with 8 solenoids placed in strategic positions around the cabinet. Even the whirring of play-field motors is replicated by a hidden Volkswagen wiper motor. Optimus also comes with a complete light show including RGB LED strips, strobes, and a shaker to rattle the entire cabinet.
If you want to see more pinball projects check out our brand new pinball projects list! If I missed your project, don’t be shy! Just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!
Last time I talked about getting started with CPU design by looking at older designs before trying to tackle a more modern architecture. In particular, I recommended Caxton Foster’s Blue, even though (or maybe because) it was in schematic form. Even though the schematics are easy to understand, Blue does use a few dated constructs and you probably ought to build your take on the design using your choice of VHDL or Verilog.
In my case, my choice was Verilog. You can find my implementation of Blue on Opencores.org. I made quite a few changes to Foster’s original design. For example, armed with semiconductor memory, I managed to get all instructions to operate in one major cycle (which is, of course, 8 minor cycles). I also modernized the clock generation and added some resources and instructions.
We are just two weeks away from the Hackaday | Belgrade conference, and tickets have completely sold out. That means you can’t get your hands on one of these sweet hardware badges, but you can still take home some prizes for pulling off a gnarly hack with the badge firmware.
What we’re talking about is the Hackaday Belgrade Badge Demoscene – which includes a surrogate presenter program for anyone who wants to send in their own code for the device. You have two weeks to work on and submit your code — and we’ve made it really easy for anyone who has a working knowledge of C.
The day of the conference we will download all entries, and have a surrogate at the conference load it onto their badge and present it on your behalf. There is a separate pool of prizes for online entries, so hackers not at the con will win. And of course we’ll be celebrating the awesome demos with some posts on the front page.
No Hardware Needed
Badge emulator scrolling the word “Hackaday”
Hack in C for Abstracted Bliss or Be Hardcore:
You can use the emulator shown here to write your code for this badge. It comes with a set of basic functions that abstracts away the low-level hardware functions, and launches a demo window on your computer to test out your code. Check out this barebones C framework to get started.
For those that want more control, we have published the official assembly code that the badges will ship with (including a user manual). We’ll be squashing bugs right up to the day of the con). You can alter and compile this code yourself, or just start from scratch using the design spec if you prefer to travel the hardcore bit-monkey path.
Either way, you have an 8×16 display and 4 buttons to work with. Exercise your creativity and amaze us by doing a lot on a rather modest canvas. That’s what demoscene is all about.
How to Enter
Entry is easy, just start a project on Hackaday.io and submit it to the Belgrade Badge Demoscene contest using the “Submit Project To…” menu on your project page. You need to upload .C and .H files, or a precompiled .HEX to the file hosting part of your project page by Saturday, April 9th.
That’s the extent of the requirements. But it would be super fun if you recorded the software emulator playing your demo for all to see. The easiest way to do this is to record a video of your computer screen using your smartphone. Good luck to all!
When most of us think of forge work, the image that comes to our mind is likely to be a rather traditional one, of the village blacksmith’s shop, roaring coke-fired hearths, and an anvil ringing to the beat of hand-wielded hammers. Iron and steel, worked through the sweat of the human brow.
Precision metalwork probably doesn’t figure in there, yet there is another type of forging used to create some of the most highly stressed components on rockets, missiles, and aircraft as well as the more mundane ironwork of your garden fence. Drop forging allows reproducible shapes to be forged while maintaining tight control over the metallurgical properties of the finished product, exactly what is required for such high-performance applications.
The video below is a promotional film about drop forging in the aeronautical industry from the late 1950s, made for and about Wyman Gordon, still specialists in the field. With the charming optimism of the period and a very catchy title it goes into the detail of the plant, development, and quality control of a range of parts for the missiles and rockets of the day, and along the way shows the cutting edge of machine tooling in the days before CNC. A whole Periodic Table of metals are forged with an expertise probably not seen in many other places in the world.
There are also some sights you’d never see in today’s safety culture, for example a running press with men darting in to adjust the position of a forging while it is still moving. It’s not a short video, but definitely worth watching all the way through.
How do you make things move? You add in a motor that converts electrical energy into motion. That’s a simple idea, but how do you know where the motor is? That’s where the servo motor comes in. By adding a sensor and a controller to the mechanism, these motors can figure out how far they have rotated and maintain that setting without any need for external control.
A disassembled servo motor showing the controller, motor, rotary encoder and gears. By oomlout, CC BY-SA 2.0
What is a Servo Motor?
These neat devices can be large or small, but they all share the same basic characteristics: a motor connected to a gearing mechanism and an encoder that detects the movement and speed of the motor. This combination means that the controlling device doesn’t need to know anything about the motor itself: the controller on the servo motor handles the process of feeding the appropriate power to the motor until it reaches the requested position. This makes it much easier to build things with servomotors, as the designer has already done all the hard work for you.
The first place that most people encounter a servo motor is in the small hobby servos that are used in remote control vehicles. Manufactured by companies like Hitec and Futaba, these drive a gear or arm that transfers the rotation of the motor to perform tasks like turning a wheel to steer a car, moving a control surface on an RC plane, or any task that requires a small range of motion at high precision. The gearing in the servomotor offers more torque than connecting the shaft directly to the motor. Most hobby servos of this type are restricted to a certain range of motion (usually 180 degrees) because the position encoder is a simple potentiometer connected to the output shaft.
A selection of different sized servo motors. By Osamu Iwasaki
Servomotors usually have three connection wires: a power line, a ground line and a signal line. The signal line is fed a pulse width modulation (PWM) signal that determines the angle that the servomotor moves to. As the name suggests, the length of the pulse (or the width, if you look at it on an oscilloscope) is the thing that controls the angle that the servo moves to: a short pulse (1 millisecond) sets it to the zero angle, while a long pulse of 2 milliseconds sets it to the maximum angle. A pulse length between these two limits signals the servomotor to move to the corresponding angle: 1.5 ms would set it to 90 degrees.
It is important to note that servomotors and stepper motors are not the same thing. Both are used for positioning, but steppers usually run without feedback. Instead, steppers turn (as the name suggest) in discrete steps. To figure out where a stepper motor is requires a limit switch, then driving the stepper until this is triggered. Then if you keep count out the number of steps that it’s traveled, you know where it is. That’s why devices like inkjet or 3D printers will move to their limits when they start up, so the controller can detect the far limit of the mechanism being driven, and calculate the current position from that.
How Do You Use A Servomotor?
Because the designers of servomotors have done most of the hard work for you, servomotors are very easy to use. To drive them, you just need to feed them power (usually 5V) and feed the PWM signal to the servomotor. You can drive them directly from an Arduino or similar microcontroller using a library that converts an angle into a PWM signal on one of the output pins.
Each servomotor requires a dedicated output pin if they are being driven this way, though, so if you are driving a lot of servomotors, a dedicated controller makes more sense. Devices such as the Adafruit Servo Shield and the Pololu Maestro allow you to control multiple servos from a single output pin on the microcontroller: the microcontroller sends a signal to the device addressing each servo in turn, and the device converts this into the PWM signals for each. If you need to drive a lot of servos, the SD84 can control up to 84 servos at once from a single USB port.
