Posts with «arduino» label

Vintage IBM Daisywheel Prints Again after Reverse Engineering

Just before the dawn of the PC era, IBM typewriters reached their technical zenith with the Wheelwriter line. A daisy-wheel printer with interchangeable print heads, memory features, and the beginnings of word processing capabilities, the Wheelwriters never got much time to shine before they were eclipsed by PCs. Wheelwriters are available dirt cheap now, and like many IBM products are very hackable, as shown by this simple Arduino interface to make a Wheelwriter into a printer.

[Chris Gregg] likes playing with typewriters – he even got an old Smith Corona to play [Leroy Anderson]’s The Typewriter – and he’s gotten pretty good with these largely obsolete but lovable electromechanical relics. Interfacing a PC to the Wheelwriter could have been as simple as scrounging up an original interface card for the machine, but those are like hen’s teeth, and besides, where’s the sport in that? So [Chris] hooked a logic analyzer to the well-labeled port that would have connected to the interface card and reverse engineered the somewhat odd serial protocol by banging on keys. The interface he came up with for the Wheelwriter is pretty simple – just a Light Blue Bean Plus and a MOSFET to drive the bus high and low for the correct amount of time. The result is what amounts to an alphanumeric printer, but with a little extra code some dot-matrix graphics are possible too.

Having spent a lot of time reverse engineering serial comms, we can appreciate the amount of work this took to accomplish. Looking to do something similar but don’t have the dough for a logic analyzer? Maybe you can free up $22 and get cracking on a similarly impressive hack.

[via r/arduino]


Filed under: Arduino Hacks, misc hacks

C64 Keyboard Emulation Over Serial

There’s a lot of reasons you might want to emulate the keyboard on your Commodore 64. The ravages of time and dust may have put the original keyboard out of order, or perhaps you need to type in a long program and don’t fancy pecking away with the less-than-stellar feedback of the standard keys. [podstawek] has come up with the solution: a Commodore 64 keyboard emulator that works over serial.

It’s a simple concept, but one that works well. A Python script accepts incoming keypresses or pre-typed text, then converts them into a 6-bit binary code, which is sent to an Arduino over the serial connection. The Arduino uses the 6-bit code as addresses for an MT8808 crosspoint switch.

MT8808 Functional Diagram from Datasheet

The MT8808 is essentially an 8×8 matrix of controllable switches, which acts as the perfect tool to interface with the C64’s 8×8 keyboard matrix. Hardware wise, this behaves as if someone were actually pressing the keys on the real keyboard. It’s just replacing the original key switches with an electronic version controlled by the Arduino.

[podstawek] already has the setup working on Mac, and it should work on Linux and Windows too. There’s a little more to do yet – modifying the script to allow complex macros and to enable keys to be held – so check out the Github if you want to poke around in the source. Overall it’s a tidy, useful hack to replace the stock keyboard.

The C64 remains a popular platform for hacking — it’s even had a Twitter client since 2009.


Filed under: classic hacks, computer hacks

An Arduino-powered automatic guitar footswitch

If remembering to hit your foot pedal at the right time during shows is a challenge, this device will take care of it for you.

As creator Franco Molina points out, there’s a lot to worry about when playing guitar in front of an audience. Actually playing is one thing, but you have to pay attention to the crowd, move around on stage, make sure you don’t have any wardrobe malfunctions, and… hit a footswitch to change between clean and distorted channels when appropriate.

Molina’s device may not be able to help you with everything on that list, but by listing to a specially encoded ‘click track’ from a computer or MP3 player, it can automatically switch amplifier modes when appropriate. It does this by using an Arduino Uno along with an amp to listen to the track, then switch a relay to simulate a footswitch.

If you’d like to build your own, check out Molina’s Instructables project page!

Crippled Calculator Features Unlocked with Automated Help

[Aguilera Dario] likes his Casio fx-82ES calculator. However, it was missing a few functions, including complex numbers. A Casio fx-991ES has more functions but, of course, costs more. A quick Google revealed that if you press the right buttons, though, you can transform an fx-82ES into an fx-991ES.

Because it is apparently a buffer overflow exploit, the hack involves a lot of keys and once you cycle the power you have to do it again. [Aguilera] realized this would be a good candidate for automation and added a microcontroller to push his buttons. You can see a video of a breadboard version below. He also has a PCB version in the works that should be better integrated.

The automation hardware patches into the button matrix through test pads on the back of the calculator’s PCB. [Aguilera] soldered ribbon cable directly to these pads, then snaked it out through a slot cut into the back of the calculator case where it is terminated with a 0.1″ pin socket. An Arduino Mini is used in the prototype, the next revision will use an ATmega328P on a custom board. The uC interfaces with the button connections using the venerable 4066 chip which is able to act as an analog switch.

The board layout for the PCB version is shown on the project page. There is no word on whether this is meant to be a permanent addition to the calculator, or just plugged in for the exploit and stored away for use the next time power is cycled. Either way, it’s neat to learn about this exploit and a cool challenge to automate it!

If you don’t want to hack up an off-the-shelf calculator, grab some nixie tubes and make your own. Or, if you are short on tubes, try this one.


Filed under: Arduino Hacks

CrashSpace BigButton w/ ESP8266

At CrashSpace we have a publicly-viewable “sign” at https://crashspacela.com/sign/ to let members know when the space is open. This sign page is updated by a big button in the front room. Press it, the sign page updates, and you’ve promised to be in the space for an hour. But last month, the button broke. So I [...]
Todbot 13 Jan 08:40

X Marks the Clock

There’s no shortage of Arduino-based clocks around. [Mr_fid’s] clock, though, gets a second look because it is very unique looking. Then it gets a third look because it would be very difficult to read for the uninitiated.

The clock uses three Xs made of LEDs. There is one X for the hours (this is a 24-hour clock), another for the minutes, and one for the seconds. The left side of each X represents the tens’ digit of the number, while the right-side is the units.

But wait… even with two segments on each side of the X, that only allows for numbers from 0 to 3 in binary, right? [Mr_fid] uses another dimension–color–to get around that limitation. Although he calls this a binary clock, it is more accurately a binary-coded-decimal (BCD) clock. Red LEDs represent the numbers one to three. Green LEDs are four to six. Two blue segments represent seven to nine. It sounds complicated, but if you watch the video, below, it will make sense.

This isn’t [Mr_fid’s] first clock. He is using a DS1307 real time clock module to make up for the Arduino’s tendency to drift. Even if you aren’t interested in the clock, the mounting of the LEDs with plastic–and the issues he had isolating them from each other–might come in handy in other displays.

We’ve seen a lot of Arduino clocks over the years, including some that talk. We’ve even seen some that qualify as interactive furniture, whatever that is.


Filed under: Arduino Hacks, clock hacks
Hack a Day 13 Jan 03:00

These students created their own Overwatch VR rig

A group of high school students in South Korea have created a multi-part rig that lets them play Overwatch in virtual reality.

Their console, which resembles somewhat of a Virtuix Omni treadmill, enables users to move around the battlefield by leaning in whichever direction they want to go, to fire and reload their weapon with a custom toy gun controller, and even to hit things by punching the air.

As you can see in the video below, the setup consists of a Samsung Gear VR headset, a smartphone, Arduino boards, an IMB sensor, a button, a ball bearing, a PC, a motion detection device, and a copy of Overwatch.

Although there’s a bit of input lag, it’s still an incredible project by a team of young Makers. You can read more on PC Gamer.

CrashSpace BigButton w/ ESP8266

At CrashSpace we have a publicly-viewable “sign” at https://crashspacela.com/sign/ to let members know when the space is open. This sign page is updated by a big button in the front room. Press it, the sign page updates, and you’ve promised to be in the space for an hour. But last month, the button broke. So I [...]
Todbot 12 Jan 18:40

Baby’s First Hands-Free Stroller

So you’ve had your first child. Congratulations; your life will never be the same again. [Dusan] was noticing how the introduction of his children into his life altered it by giving him less time for his hobbies in his home laboratory, and decided to incorporate his children into his hacks. The first one to roll out of his lab is a remote-controlled baby stroller.

After some engineering-style measurements (lots of rounding and estimating), [Dusan] found two motors to drive each of the back wheels on a custom stroller frame. He created a set of wooden gears to transfer power from the specialized motors to the wheels. After some batteries and an Arduino were installed, the stroller was ready to get on the road. At this point, though, [Dusan] had a problem. He had failed to consider the fact that children grow, and the added weight of the child was now too much for his stroller. After some adjustments were made (using a lighter stroller frame), the stroller was eventually able to push his kid around without any problems.

This is an interesting hack that we’re not sure has much utility other than the enjoyment that came from creating it. Although [Dusan]’s kid certainly seems to enjoy cruising around in it within a close distance to its operator. Be sure to check out the video of it in operation below, and don’t forget that babies are a great way to persuade your significant other that you need more tools in your work bench, like a CNC machine for example.


Filed under: wireless hacks

Attachment is like a modern-day message in a bottle

If you want to reach out to someone, you could always pick up your phone and send a text. But if you’re seeking something a bit more random and indirect, one idea would be to write and attach a message to a biodegradable balloon using Swiss designer David Colombini’s “poetic machine.”

Colombini’s Attachment project allows you to do just that, by dispatching digital notes, images or videos gleaned from the Internet into the atmosphere. Once the Arduino Mega-driven device receives this input, the message is laser-etched on a thin piece of balsa wood, then released into the air (though a human has to ‘reload’ after five launches). Word space is limited to a Twitter-esque 120 characters, but the finder of the balloon can access any additional content that you include through a code on the project’s website.

According to Creative Applications:

Software includes PHP / MySQL database, vvvv (take the message from web database, layout of the message, transform it and stream it to the engraver) and Arduino IDE (controlling all the mechanisms). Hardware includes an Arduino Mega, NEMA 23 motors + drivers, linear actuators, a Bambi air compressor, helium cylinder, Festo pneumatic components (helium + air valves, helium and air pressure sensors, pneumatic cylinders, DHEB) and MicroSlice engraver (based on Arduino Uno).

You can read more on this project as well as its previous version. Additionally, visit the Attachment.cc page to input your own message!

(Photos: David Colombini)