A Z80 Computer With Switches And Blinkenlights

December 1, 2014 by 50 Comments

While most people who build their own computer from chips want the finished product to do something useful, there’s something to be said about a huge bank of switches and a bunch of blinkenlights. They’re incredibly simple – most of the time, you don’t even need RAM – and have a great classic look about them.

[Jim] wanted to build one of these computers and wound up creating a minimal system with switches and blinkenlights. It’s based on the Z80 CPU, has only 256 bytes of RAM, and not much else. Apart from a few extra chips to output data and address lines to LEDs and a few more to read switches, there are only two major chips in this computer.

With the circuit complete, [Jim] laser cut a small enclosure big enough to house his stripboard PCB, the switches and LEDs, and a few buttons to write to an address, perform a soft reset, and cycle the clock. One of the most practical additions to this switch/blinkenlight setup is a hand crank. There’s no crystal inside this computer, and all clock cycles are done manually. Instead of pushing a button hundreds of times to calculate something. [Jim] added a small hand crank that cycles the clock once per revolution. Crazy, but strangely practical.

[Jim] made a demo video of his computer in action, demonstrating how it’s able to calculate the greatest common divisor of two numbers. You can check that video out below.

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Home Automation Setup Keeps You Informed

December 1, 2014 by 8 Comments

[johannes] wrote in to tell us about his latest project, a home automation setup he named Botman. While he calls it a home automation system, controlling lights and home appliances (which it does wirelessly on 433MHz) is just a small part of its functionality. The front panel of Botman includes a servo which points to laser-etched icons of the current weather. It also has a display which shows indoor and outdoor weather conditions along with the status of public transportation around [johannes]’s house.

Botman is built around an Arduino with an Ethernet shield. The Arduino has very little memory, so [johannes] used the Google Apps engine as a buffer between his Arduino and the JSON APIs of his data sources. This significantly reduces the amount of data the Arduino has to keep in memory and parse.

[johannes] also wrote an Android app that communicates with Botman. The app has buttons for controlling lights in his house and duplicates all the information shown on the front panel. [johannes] also built some logging features into Botman. The temperature readings and other information are uploaded from the Arduino to a Google Docs spreadsheet where he can view and graph them from anywhere. Check out the video after the break to see Botman in action.

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3D-Printed Clock Tells Time With Gears

December 1, 2014 by 52 Comments

[ekaggrat] designed a 3d-printed clock that’s fairly simple to make and looks awesome. The clock features a series of 3d-printed gears, all driven by a single stepper motor that [ekaggrat] found in surplus.

The clock’s controller is based around an ATtiny2313 programmed with the Arduino IDE. The ATtiny controls a Darlington driver IC which is used to run the stepper motor. The ATtiny drives the stepper motor forward every minute, which moves both the hour and minute hands through the 3d-printed gears. The hour and minute are indicated by two orange posts inside the large gears.

[ekaggrat] etched his own PCB for the microcontroller and stepper driver, making the build nice and compact. If you want to build your own, [ekaggrat] posted all of his design files on GitHub. All you need is a PCB (or breadboard), a few components,  and a bit of time on a 3D printer to make your own clock.

3D Printing Atomic Force Microscopy

December 1, 2014 by 15 Comments

[Andres] is working with an Atomic Force Microscope, a device that drags a small needle across a surface to produce an image with incredible resolution. The AFM can produce native .STL files, and when you have that ability, what’s the obvious next step? That’s right. printing atomic force microscope images.

The AFM image above is of a hydrogel, a network of polymers that’s mostly water, but has a huge number of crosslinked polymers. After grabbing the image of a hydrogel from an Agilent 5100 AFM, [Andres] exported the STL, imported it into Blender, and upscaled it and turned it into a printable object.

If you’d like to try out this build but don’t have access to an atomic force microscope, never fear: you can build one for about $1000 from a few pieces of metal, an old CD burner, and a dozen or so consumable AFM probes. Actually, the probes are going to be what sets you back the most, so just do what they did in olden times – smash diamonds together and look through the broken pieces for a tip that’s sufficiently sharp.

Using The Second Microcontroller On An Arduino

November 30, 2014 by 45 Comments

While newer Arduinos and Arduino compatibles (including the Hackaday.io Trinket Pro. Superliminal Advertising!) either have a chip capable of USB or rely on a V-USB implementation, the old fogies of the Arduino world, the Uno and Mega, actually have two chips. An ATMega16u2 takes care of the USB connection, while the standard ‘328 or ‘2560 takes care of all ~duino tasks. Wouldn’t it be great is you could also use the ’16u2 on the Uno or Mega for some additional functionality to your Arduino sketch? That’s now a reality. [Nico] has been working on the HoodLoader2 for a while now, and the current version give you the option of reprogramming the ’16u2 with custom sketches, and use seven I/O pins on this previously overlooked chip.

Unlike the previous HoodLoader, this version is a real bootloader for the ’16u2 that replaces the DFU bootloader with a CDC bootloader and USB serial function. This allows for new USB functions like HID keyboard, mouse, media keys, and a gamepad, the addition of extra sensors or LEDs, and anything else you can do with a normal ‘duino.

Setup is simple enough, only requiring a connection between the ‘328 ISP header and the pins on the ’16u2 header. There are already a few samples of what this new firmware for the ’16u2 can do over on [Nico]’s blog, but we’ll expect the number of example projects using this new bootloader to explode over the coming months. If you’re ever in an Arduino Demoscene contest with an Arduino and you’re looking for more pins and code space, now you know where to look.

3D Printing Without Support

November 30, 2014 by 12 Comments

3D printing is getting better every year, a tale told by dozens of Makerbot Cupcakes nailed to the wall in hackerspaces the world over. What was once thought impossible – insane bridging, high levels of repeatability, and extremely well-tuned machines – are now the norm. We’re still printing with supports, and until powder printers make it to garages, we’ll be stuck with that. There’s more than one way to skin a cat, though. It is possible to print complex 3D objects without supports. How? With pre-printed supports, of course.

[Markus] wanted to print the latest comet we’ve landed on, 67P/Churyumov–Gerasimenko. This is a difficult model for any 3D printer: there are two oversized lobes connected by a thin strand of comet. There isn’t a flat space, either, and cutting the model in half and gluing the two printed sides together is certainly not cool enough.

To print this plastic comet without supports, [Markus] first created a mold – a cube with the model of the comet subtracted with a boolean operation. If there’s one problem [Markus] ran into its that no host software will allow you to print an object over the previous print. That would be a nice addition to Slic3r or Repetier Host, and shouldn’t be that hard to implement.

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Hackaday Links: November 30, 2014

November 30, 2014 by 6 Comments

Tired of wiring up the power rails and serial adapter every time you build something on a breadboard? [Jason] has you covered. He put his Breadboard Buddy Pro up on Indiegogo, and it does everything you’d expect it to: power rails, USB to UART bridge, and a 3.3 V regulator. Oh, he’s not using an FTDI chip. Neat.

With Christmas around the corner, a lot of those cheap 3-channel RC helicopters are going to find their way into stockings. They’re cool toys, but if you want to really have fun with them, you’ll need to add a penny.

Here’s a crowdfunding campaign for a very interesting IoT module. It’s a UART to WiFi adapter that has enough free Flash and RAM to run your own code, GPIOs, SPI, and PWM functions. Wait a second. This is just an ESP8266 module. Stay classy, Indiegogo.

Mankind has sent space probes to the surface – and received pictures from – Venus, Mars, the Moon, Titan, asteroids Itokawa and Eros, and comet Comet 67P/Churyumov–Gerasimenko. In a beautiful bit of geological irony, every single one of these celestial bodies looks like a rock quarry in Wales. That quarry is now for sale.

Here’s something exceptionally interesting. It’s a browser plugin that takes a BOM, and puts all the components into a cart. Here’s the cool bit: it does it with multiple retailers. The current retailers supported are Mouser, Digikey, Farnell/Element14, Newark, and RS Components.

Want a death ray? Too bad, because it’s already been sold.