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Displaying tweets with a laser pointer and speakers

 

This year at Toorcamp, [Rich] will be showing off his laser-based vector display, capable of projecting tweets using only a laser pointer, a pair of mirrors, speakers, and an Arduino. Steady hand and curses from lack of an optical bench not included.

 

[Rich]‘s Instructable goes over the finer points of the build; a Python script runs on his computer fetching all recent tweets with a certain hashtag. These tweets are sent over to a ‘duino where a bit of code translates the text into a scrolling vector display. The code for the project is based on one of [Rich]‘s previous builds to draw shapes with the same speaker/laser setup.

In theory, using a pair of speakers to draw text on a wall isn’t much different from drawing pictures on an oscilloscope. Of course, [Rich] always has the option of turning his LaserTweet into an oscilloscope when Toorcamp is over.

Relevant videos after the break.

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4004 ROM emulator allows fast development on slow computers

 

Developing for extremely old computers is a chore; not only are you limited by assembly or pure machine language, there’s also the issue of burning ROMs to actually run your programs. [Frank Buss] came up with a neat solution to developing for the venerable 4004 CPU – build a ROM emulator using a modern microcontroller.

The build started off with a ZIF socket for the 4004 CPU and a 256 byte 4001 ROM chip emulated on a PIC micro. The CPU looked a little lonely sitting in the ZIF socket all by its lonesome, so [Frank] updated his board to allow a 4002 RAM chip to be plugged in as well.

Because [Frank] chose a 4004 for his entry for this season’s retrochallenge competition, we need to point we’re offering a prize for loading our retro site with this CPU. Yes, it’s most likely impossible but nothing worth doing is easy.

You can check out a video [Frank]‘s ROM emulator after the break.

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Hundred dollar capacitive discharge welder

 

[Robert] needed to weld metal tabs on a few batteries. In a proper manufacturing situation, this is usually done with outrageously expensive welders. Not wanting to spend thousands of dollars to attach bits of metal together, [Robert] built his own capacitive discharge welder for only $100.

Instead of the giant transformers you’d find in a spot welder, a capacitive discharge welder uses a huge bank of capacitors – greater than 1 Farad – to weld pieces of metal together. Huge caps like these are commonly used for ridiculous car stereo setups, so with the addition of a car battery charger purchased from Walmart, [Robert] had most of a welder on his workbench.

To control the mass of power coming from his huge cap, [Robert] used a 13o amp Silicon controlled rectifier to improve the control of his welder. With the battery charger, cap, and SCR, [Robert] only needed a few bits of heavy gauge wire to tie the entire build together.

[Robert]‘s build welds metal tabs on battery terminals beautifully, but the possibilities don’t end there. This welder could easily be repurposed to build the skeleton of outrageously intricate dead bug circuits, or maybe even keeping that thing you made with your Erector set in one piece permanently.

Telepresence robot with Skype connectivity

[Claire] sent in a project she’s been working on for the past few years. It’s called Botiful and aims to turn any Android phone into a mobile telepresence robot.

Botiful is built around the IOIO Android to Arduino dev board and provides a very clean way to interface your current cell phone with a tiny – and cute – robotic platform. The big feature of Botiful is its integration with Skype; just call a Botiful owner’s phone or tablet, and a panel pops up allowing you to control the robot, tilt the camera up and down, and even robotic yes, no, and ‘dance’ gestures.

Because Botiful is based on the IOIO, there’s a few pins available inside the bot for an I2C bus, PWM control, and even a serial output. It’s also possible to develop your own apps for Botiful, making for a neat mobile robotics platform.,

Right now, Botiful is only for Android but if [Claire] gets $100,000 out of her Kickstarter, she’s promised to add iDevice support. That seems fairly likely, as more than $60,000 has been pledged with three weeks to go. Pretty cool, and we can think of a few very useful asocial applications of the Botiful including running cable in a drop ceiling, and checking out that thing under your car.

Arduino Taipan! clone stays true to the original

taipan

Fans of vintage Apple ][ and TRS-80 games will undoubtedly recognize the image above in short order. Taipan! was a popular game in its time, and [Simon] decided it was a great title to try recreating with an Arduino.

His goal was to use a standard Arduino Duemilanove to reproduce the game, rather than opting for a Mega or something like the Raspberry Pi. Seeing those two options as “too easy”, he ventured into the project with some self-imposed limitations, making it a more fruitful adventure.

In the end, [Simon] had to use two Arduinos – one to control the gameplay and another to run the display. Simon tucked both boards, a keypad, and an LCD screen inside a first run copy of Tai-Pan, a move that is sure to please Apple aficionados and Xzibit fans alike.

[Simon] made sure that no detail was overlooked during the port, making sure to include every line of text as well as every bug found in the original game.

Check out a video of the finished project below, and be sure to swing by his site for a very thorough build log.

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