Little, no name, 1.5 inch LCD photo key-chains are all over the place for practically nothing. Not too surprisingly these things do not vary much in the parts that they use, some flash ram, a little lipo battery and a 16 bit color LCD. Wanting to find a way to reuse that LCD [Simon] Has an excellent tutorial on how to reuse a FTM144D01N LCD with a ILITEK ILI9163 LCD driver for your electronic projects.

Two units were used, one was ripped apart and soldered to a home made breakout board, the other was kept intact so its logic could be sniffed out with an oscilloscope. A pin-out was quickly determined since these things typically use a 8 or 16 bit data bus. Then a driver library was put together for AVR micro controllers, which includes some basic shape drawing and a 5×8 font.

While you may not be lucky enough to get this exact LCD screen from your local bargain store, there are a lot of pointers in here to hopefully get you up and going. We will be trying our luck on a very similar screen this afternoon as these things do have a decent picture and fairly quick response times already packaged in a hand-held case.

Join us after the break for a quick video.

Part of the fun with old computers is playing some old school games, and while you could play them with a keyboard it is much more fun with a joystick. You can get old joysticks all day long on auction sites, but you have to watch out. Some are digital, which wont work for many games on many systems. Some were cheap to begin with and probably worn out, and many are flight sticks … ever play pac-man with a giant flight stick?

What I really wanted was a game pad like device for my 1986 Apple //c , using one of the modern thumbstick analog controllers. Using a thumbstick out of an old XBOX(1) controller, some generic parts from Radio Shack, and a little bit of effort , I ended up with exactly what I wanted.

Join us after the break and I will show you how to get there!

First some basics, most computers that have analog controllers implement it in a pretty simple method. In a nutshell there is a 555 timer wired up for single shot mode, the computer triggers the 555 and counts how many cycles pass before the 555′s output changes. One of the potentiometers inside the joystick is hooked up to this circuit and controls the rate that a capacitor charges. Once filled the 555 changes output. Swing the joystick one way, resistance increases and the capacitor takes longer to charge. Swing it the other way resistance lowers, cap charges faster. Simple right?

Now just multiply 555′s for how many axis you need and you have a simple analog joystick. Apple //s, and IBMs work like this, and use a 556 dual timer (one, two axis joystick) or a 558 quad timer (two, two axis joysticks). Below is an example circuit from the Apple //c Technical Reference Manual.

Other computers like the 8 bit Commodore’s and Atari’s used this setup for their paddle controllers which were often in joystick or flightstick format. About the only one I know of that does not handle analog joysticks in this manner is the Tandy TRS series, but I am sure there are others. Check with your computers nerd club before proceeding.

Next thing to consider is the values of the potentiometers inside of your joystick. the most standard value for old computers is 100K ohm. Apple used 150K ohm. Why? I don’t know but with Apple stuff, if its hard to source, they will use it. Thumbsticks themselves come in all varieties of resistance, from places like Digikey. If you don’t mind spending a couple bucks + postage, that might be the best way for you.

Since I am using scavenged thumbstick from an XBOX controller I don’t have a choice of what value it is. The thumbsticks that come stock with that controller is 10K ohm. In order to compensate for the difference in resistance,we just need to add more capacitance.

Before I go bothering myself with math, I need to find out exactly where my joystick “tops out” while its in its enclosure. I went out an purchased a 4x2x1 inch enclosure from Radio Shack, and while I was there I also picked up a couple panel mount normally open pushbutton switches.

With these radio shack project boxes, they give 2 choices of a lid, a nice molded plastic lid that sits on top of the box, and an aluminum panel that sits a bit recessed in the box. I just had to have that aluminium panel for looks, but it ended up causing a bunch of problems.

First I had to cut the lip of the box off where the panel would not be recessed anymore. That was accomplished using some 90 degree flush cut wire trimmers and a file. Because I lost about a quarter of an inch in height, the thumbstick would not fit anymore using the screw mounts inside the box. I had to snap off the screw mounts, then flatten the area where they broke off with a chisel. Then I surface mounted everything to a piece of pad-per-hole perfboard flipped upside down, since the only way the thumbstick would fit is if the board was flat against the bottom.

With all of that sorted out, I went to drill holes into the aluminum panel. I drew the outline of the panel on some paper, and I was measuring everything out. I didn’t like how the holes were sitting, so in the end I just simply eyeballed them on paper. Then I taped the paper to the aluminum plate and made divots for the hole centers with a hammer and nail.

The aluminum plate was then screwed to a scrap chunk of 2×4 wood, and drilled. I used a 1 inch hole saw for the joystick (which is a bit too large) and quarter inch holes for the switches. I used a jewelers file to quickly deburr the holes, but the large joystick hole was still a little rough. To give a more finished appearance I decided that it needed a grommet.

I went to the local hardware store, and when I asked for a grommet with about a 1 inch inside diameter, they looked at me like I just stabbed a baby. I ended up at Lowes where I found a grommet in one of the “hard to find” bins in the screw section with a 1&1/8th outside diameter, and a 23/32nds inch (18.25 ish mm) inside diameter, which is good enough. The grommet was much too tall to fit both inside and outside of the box, so I just simply chopped its top off and glued it down with some goop (super strong and thick glue).

Now that the box is in order I can see where my thumbstick tops out at. I bent the leads of the thumbstick out to a 90 degree angle so I could surface mount them to the perfboard. Then I soldered it down and added some test leads, ran the wires out of a hole I drilled in the back of the box for the joysticks cable, and popped on the lid.

Using a multimeter I found out that it the furthest I could push the thumbstick came out to about 8.5K ohm on both axis. My meter is overkill for most of what I do, so I could have used the 5 digits of accuracy, but its not needed. I will add some trimpots later for fine tuning.

Now that I know 8.5K is my max resistance, its time to figure out how much capacitance I need to add so that the circuit internal to the computer will behave the same with this 10K pot as it did with a 150K. The formula to calculate the capacitance is pretty simple:

((original_potentiometer_value * internal_timing_capacitor) / new_potentiometer_value) – internal_timing_capacitor

Most of the time the internal timing capacitor is 0.022 uf, though you might want to check before assuming for your machine. The original potentiometer value of the Apple // is 150K ohm so…

((150,000 * 0.022) / 8500) – 0.022 = 0.366235294

Therefore we need to add about 0.36uf in parallel to the joystick so that a 10K pot works the same as a 150K pot in the timing circuit. My capacitor selection pretty much stinks so I ended up using 3, 0.1uf capacitors in parallel and 2, 0.1uf in series per axis, giving me about 0.35uf. It does not have to be exact because I also added a 10K trimpot in series with the capacitors which will allow me to control how fast the extra caps charge, giving a fine tuning mechanism. Below you will see the schematic I ended up with for my Apple //c.

Now it is just a matter of wiring everything up, connecting buttons and a cable, and then using a test program to calibrate the thumbstick. The Apple //c has a nice diagnostic program which also test’s joysticks, but you could just as easily write one up in basic. For example, in Applesoft:

10 X=PDL(0): FOR I=1 TO 10: NEXT: Y=PDL(1)
20 PRINT X " " Y " " PEEK(49249) , PEEK (49250)
30 GOTO 10

To calibrate I just need to adjust the trimpots until its about center, the program above shows value from 0-255, and we can give ourselves about 5% in error, from there its just a matter of making sure the thumbstick maxes the readouts when in its most extreme up/down/left/right positions. Some error is ok, and a little jitteryness in center is fine as well.

Anyone who has programmed for analog controllers quickly figure out a little dead space for middle and a little room for error on the extremes is needed whether it be a 26+ year old computer, or a brand new Sony PSP, nothing is 100% perfect.

Once the thumbstick is calibrated to the computer its time to button it up and play some retro games. How well does it work? Pretty darn good, I may go back and drill a couple small holes so I can fiddle with the trimpots without having to take it apart, but other than that it plays good and looks nice (IMO) .

Thanks for reading!

(Reference: The Computer Controller Cookbook)

Every once in a while, the Hack a Day tip line gets a submission that is cool, but screams to be built in a few hours, possibly while consuming adult beverages. When [Shay] and [Ben] sent in their Manifold Clock Kickstarter, I knew what I had to do. To make a long story short, there’s a manifold clock hanging on my wall right now. Check out my manifold clock how-to guide after the break.

As designed by [Shay] and [Ben] at Studio Ve, the Manifold Clock tells time in three dimensions and is based on the log z Riemann surface. Here’s the video the guys put up on their Kickstarter campaign:

As you can see, it’s not a terribly complicated build. There are three basic components for this build. First, the clock drive: these can be had for about $5 from any arts and crafts store. Secondly, the clock hands: not many clock drives come with a six-inch long minute hand, but I can make something work. Lastly, the webbing that goes between the hands. The official version of the Manifold Clock uses Tyvek for its tear resistance, but I came up with something just as cool.

To create the long clock hands, I repurposed the clock hands that came with the clock drive. By cutting of the largest part of the hour and minute hand, I was left with a small sliver of brass that can be attached to the hub of the clock. I bought a few pieces of brass tubing while I was in the hobby shop, as well. The hands of the clock were extended by soldering on brass tubing with 0.1″ or 2.5mm OD brass tubing:

Pardon the terrible picture. If anyone would like to donate a macro lens for a D40, I would graciously accept.

After cutting the clock hands to length, everything’s gravy. Now onto building the webbing that goes in between the clock hands.

The next two paragraphs are rather boring. Fair warning.

If you’d like to create your own manifold, just fire up your favorite CAD package and get to work. For my manifold, I first drew a circle with the same radius as the minute hand, and two more for the hour hand and center. I used a circle with a diameter of half and inch for the center – just enough to clear the hub of the clock drive. Inscribe a 12-gon in the hour hand’s circle, and draw the hour hand. I drew mine at 5 o’ clock, although this is just a rough guesstimate from watching the video for the Manifold Clock

The next step may be a little difficult if you don’t know your drawing package very well, but luckily it can be done very easily with a compass and straight-edge construction. I’ll let you Euclid that one out for yourself. Bisect the hour and minute hands, then draw a circle with a radius that is the average of the minute and hour hands. Draw an arc from the tip of the minute hand through the intersection of the bisection and circle you just drew, ending at the tip of the hour hand. Erase a few lines,  put some tabs on for gluing, and you’re done.

To save everyone from having to replicate my work, I’ve created a PDF file of the template for my clock’s membrane. This template is sized for a minute hand that is 5.5 inches long and an hour hand that is 3 inches long. Do with it what you will.

The Manifold Clock uses a piece of Tyvek for the web between the hour and minute hands. Tyvek can be had for free if you care enough to drive around to a new development and dumpster-dive for a piece of housewrap, but I wanted to make my clock a little classier. My webbing is made out of mylar (from an “emergency camping blanket” or alternatively a mylar balloon) with a layer of Kapton tape stuck to one side. The Kapton tape was originally purchased for the heated bed and hot end of my RepRap, but once I realized the gold foil on the Apollo LEM were a lamination of mylar and Kapton, I had to try this out. The result is a fairly tear-resistant film in a wonderful silver and gold:

Oh yeah, you also have to bend the minute hand higher than the hour hand.

After cutting my gold and silver film according to the template, the only thing left to do is assemble the clock. Wrap the tabs on the web around the hands of the clock, making sure the hands can rotate freely around the foil. Assemble the hands onto the clock mechanism according to the directions and mount it in some sort of enclosure. I used a fifty-cent round clock face:

So far the clock has been up on my wall for 38 hours and it’s still keeping the right time. I’m going to call this a success. Here’s a time-lapse of the clock in action:

The expenses for this build were a clock mechanism for $5.99, a small brass tube for $2.99, and an unfinished clock face for $0.50, totaling $9.49. Of course I haven’t figured in the cost of the mylar, Kapton, solder, paint, and soldering iron, but you get the point.

Sadly my clock doesn’t have a second hand and doesn’t tick very loudly so a Vetinari Clock is out of the question. If anyone is brave enough to build a Manifold Clock with a second hand, send it in. We’ll put it up.

[RandomTask] has posted a nice tutorial on how to use a FTDI serial to usb converter, and a couple analog to digital converters to make a simple software oscilloscope. Using a “Universal Serial to USB converter” and one of many FTDI break out boards, he first reprograms the chip using FTDI’s programming software to put the device into a FIFO (first in first out) mode.

From there a pair of ADC0820 8 bit digital to analog converters are wired up, and input is fed to a couple 555′s for testing. It should be noted that there is no input protection, so things like voltages above 5 volts, or negative voltages are a big no-no with this setup. It still could be very handy while working with micro controllers or other digital circuits.

Data is then sent to the computer and displayed using a VB.net program, which has some basic features like scale and triggering, but also contains a couple bonuses like Calc Freq and Calc V delta calculation.

Many people have these little serial to usb converters, and might be in need of a simple scope. If you’re one of them, then you can cobble this together pretty darn quickly, and cheaply.

FPGAs are the bee’s knees. Instead of programming a chip by telling it what to do, FPGAs allow you to tell a chip what to be. Like everything though, a new skill set is needed to fully exploit the power of FPGAs. [Mike Field] decided to give back to the internet community at large and put up a crash course in FPGA design.

Right now, [Mike] has a couple of modules up that include subjects like binary math, busses, counting, and of course setting up the FPGA hardware. The recommended hardware is the Papilio One, although the Digilent Nexys2 is what [Mike] has been using so far.

We’ve seen a ton of awesome stuff that uses FPGAs, like the emulated Mac Plus, breaking HDCP, and an Ocarina of Time. [Mike]‘s tutorials look like a great starting point for some FPGA work. [Mike] is also looking for some feedback on his tutorials, so if you’ve got an idea of what he should cover be sure to drop him a line.

EDIT: The server was running on an FPGA and we can’t find a cache anywhere. If you’ve found a mirror, send a message. Apparently Amazon’s EC2 runs on an FPGA.

As winter is officially upon us, we’re pretty sure that the last thing most of you are thinking about is mowing your lawn. We would argue that it’s actually the ideal time to do so – that is, if you are interested in automating the process a bit.

[Robert Smith] has spent a lot of time thinking about his lawn, wanting a way to sit back and relax while doing his weekly trimming. He set off for the workshop to build an R/C electric lawnmower, and thoroughly documented the process in order to help you do the same.

On his web site, you will find a series of videos detailing every bit of the solar charged R/C lawnmower’s construction, taking you through the planning phases all the way to completion. [Robert] has provided just about anything you could possibly need including parts lists, schematics, code, and more.

If the short introductory video below has you interested, be sure to swing by his site for everything you need to build one of your own.

If you’ve been reading Hack a Day for long enough, you know about our infatuation with stepper motors. These precious little devices put the oomph into our CNC routers, 3D printers, robots, and other miscellaneous projects. Steppers aren’t your run-of-the-mill motors, though. [Steaky] posted a great introduction to stepper motors that lets you hit the ground running building any moving project you could imagine.

Apart from identifying a stepper and figuring out if it works, [Steaky] goes over how to make these motors turn. The theory behind an H-bridge is easy enough, but theory isn’t something often presented in schematics or stepper driver datasheets.

We’ve pulled more than our fair share of steppers from flatbed scanners and old printers. There’s nothing wrong with scavenging old parts, and whether you’re making a robot band to play your kid’s birthday party, robochess, or one of the many 3D printers or CNC machines, there’s going to be a stepper motor in your future.

The folks over at Toymaker Television have put together another episode. This time they’re looking at bridge rectifiers and how they’re used in AC to DC converters.

This is a simple concept which is worth taking the time to study for those unfamiliar with it. Since Alternating Current is made up of cycles of positive and negative signals it must be converted before use in Direct Current circuits; a process called rectification. This is done using a series of 1-way gates (diodes) in a layout called a bridge rectifier. That’s the diamond shape seen in the diagram above.

This episode, which is embedded after the break, takes a good long look at the concept. One of the things we like best about the presentation is that the hosts of the show talk about actual electron flow. This is always a quagmire with those new to electronics, as schematics portray flow from positive to negative, but electron theory suggests that actual electron flow is the exact opposite.

OK, year-old pop culture references aside [Kyle] dropped us a line to show us his tutorial on using interrupts with your Arduino. Given the single core nature of your average Arduino’s AVR you pretty much have two choices for monitoring occasional un-timed inputs: Either check an input at an interval (which risks missing the signal entirely) or set up an interrupt to pause the chip’s normal operation. Obviously working with interrupts saves you tons of clock cycles since you are not polling a pin over and over. [Kyle] plans on a follow up tutorial to cover timer based interrupts, which can come in handy when generating frequencies and stuff.

Looking for more Arduino Basics? How about Basic on an Arduino. Check out our other beginner concepts posts as well if you need to work on your fundamentals.

Eminent steampunker [Jake Von Slatt] wrote a small article on etching candy tins for The Steampunk Bible, but the limited space available in the book didn’t allow for a full exposition. To make amends for his incomplete tutorial, he posted this walk through to compliment the Bible’s article.

The process is very similar to the many tutorials we’ve seen on home-etching PCBs using the toner transfer method. Removing the paint from the Altoid tin, creating a mask, printing it on the Sunday circulars, and taking an iron to the tin is old hat for home fabbers.

Unlike PCB manufacturing, [Mr. Von Slatt] doesn’t bother with Ferric Chloride or other nasty chemicals – he does everything with electrolysis. After adding a few tablespoons of table salt to a bucket of water, [Jake] takes a DC power supply and connects the positive lead to the lid and the negative lead to the base. a bit of electrical tape around the corners of the lid keeps the metal from getting too thin.

A nice Copper finish can be applied to a finished tin by swabbing on a solution of Copper Sulfate – a common ingredient in “Root Kill” products. Of course that’s not a necessary step; you can easily enjoy and elegant Altoid tin bare metal.

[Eric Wolfram] wrote in to let us know about a simple and cheap acoustic panel DIY he put together.  When installing a home theater acoustics are often neglected (especially if you spend so much on the TV you cannot afford any furniture for the room) resulting in reduced listening quality and poor spacial sound imaging from your surround system (also responsible for the furniture problem). The addition of sound absorbing panels helps control the acoustics of the room and may even class up the place a bit.  These are also come in handy for home studio usage where a low level of reverberation is preferred.

The panels are relatively simple to produce on a budget, just a sheet of 2″ thick dense fiberglass board glued into a wooden frame and covered in a sound-transparent fabric. [Eric] goes into a lot of the material selection process to help you along your way. The best part about the project (aside from its obvious utility) is that all of the materials can be found cheaply at your average home improvement store, with the exception of the fabric.  [Eric] mentions that you can substitute colored burlap if need be.  Once the panel is assembled and glued it just has to be hung on the wall of your choice like a large heavy picture frame. This could certainly help the acoustics and reduce some slap-back echo in your warehouse/shop. We might have to try this one over the weekend.

Thanks [Eric]!

It looks like [Dino] is getting settled into his new digs, and while the moving process has kept him pretty busy, he’s slowly but surely getting his workshop area set up. One thing that he really wanted from his new bench was a better way to record video, for both his Hack a Week series as well as broadcasting over Ustream.

He bought a nice little Hi-Def web cam for making videos and set out to build a camera boom for his bench. The boom is constructed mostly from PVC piping along with some other odds and ends for mounting. In the video below, he walks through the construction step by step, making it easy for anyone to follow along and build one of their own.

The boom looks like it works very well, and is a bargain at under $40. It articulates every which way giving him complete coverage of his workbench, and makes it easy to film whatever he’s working on – big or small.

Yup. We have all been there. You throw together a really elaborate Arduino project that only really needs a couple pins, far fewer than the Arduino’s native microcontrollers have to offer. Well fear not, [Thatcher] has solved just this problem by adding some ATTtiny cores to the Arduino IDE. His blog details the process from grabbing the MIT developed core files and loading them up in your Arduino software directories. The modification looks simple and although [Thatcher] shows the whole process on a Mac it only involves unzipping and tossing files into a folder. With ATTiny chips only a few bucks each this is perfect for those simple software driven hacks that don’t require an entire Uno duct taped to the outside of an enclosure.  Nice work [Thatcher]!

Our friend [Jeri] tipped us off about this cool video on youtube where the author makes his own “transparent” PCB’s using some nontraditional materials. One ounce copper foil is found online along with some clear glass microscope slides, from there it is just a matter of cementing the foil onto the glass slides with some thin UV curing glue. Once the 2 parts are mated the entire thing is popped into an eeprom eraser for its intense UV light, then excess is trimmed.

The normal routine of toner transfer is used to copy a circuit pattern onto the copper clad glass and it’s etched in standard ferric chloride. The copper is removed but the UV glue that was holding it is still left, some special care needs be followed as this stuff is pretty weak against even mild solvents, and you do not want your traces peeling up. Next no clean solder paste is applied and parts are soldered down with a heat gun, keeping the glass evenly heated to prevent it from cracking.
This leaves you with a board that looks like frosted glass, and in order to protect the glue while clearing up the frosted effect, some polyurethane is applied which fills in all the little bumps and smoothes the surface bout out to almost 100% clear.
The end application in this video is a touch sensitive board which works fine though the back side of the glass and presents a nice smooth interface for the user. Join us after the break for the video.

This is a fairly long video, clocking in at about 25 minutes, so be prepared to dedicate a chunk of time.