A Charming Arduino King Cobra Game

June 22, 2013 by Brian Benchoff 22 Comments

cobra

Here’s a fun game from [A.J.]’s lab. It’s a simulated king cobra made from an Arduino, an ultrasonic sensor, and a servo. The aim of the game is to grab a ball in front of the device without being ‘bitten’ by the thumbtack attached to a drinking straw controlled by a servo. You know, just like a real king cobra.

There’s no schematic or build plans for this project, but it looks easy enough to cobble together. Despite its simplicity, this game looks hilariously fun, and could quite possibly provide more entertainment through using the machine rather than simply building it.

No text description of this game can do it justice, so check out the video below. It looks like a lot of fun, and if you already have the parts in a bin somewhere, it’ll make a great weekend build.

Continue reading “A Charming Arduino King Cobra Game” →

Outputting Text On A Paper Tape Machine

June 22, 2013 by Brian Benchoff 24 Comments

thegame

Back before the days of 8 inch floppy disks, storing computer programs was much more primitive than even a stack of punch cards. The earliest general purpose computers used paper tape, a strip of paper with punched holes designating a 0 or a 1. Thankfully for the computer scientists of the day, these paper tapes weren’t created by hand. No, the Friden SP-2 tape punch took care of the duties of punching holes in these tapes. When [Max] rescued one of these tape punch machines from a trash bin, he knew what he needed to do: connect it to an Arduino so he could create his own paper tapes.

[Max] found a veroboard with a bunch of transistors inside the machine that was added by a previous owner. After finding the manual for the machine he connected it to an Arduino, holding each of the eight control pins high to punch the tape, and then holding another pin high to advance the tape. With this, he was able to punch letters instead of binary code into his paper tape.

[Max] also added an Ethernet shield to his Arduino that checks his email. If an email shows up in a special folder, it outputs the subject line to the tape punch machine, giving him an entirely retro ticker tape machine, built with vintage 60s hardware.

There are a pair of videos of [Max]’s tape punch machine in action below, along with a gallery of the glamorous gut shots of this incredible machine.

Continue reading “Outputting Text On A Paper Tape Machine” →

An Arduino Power Inverter

June 21, 2013 by Brian Benchoff 32 Comments

If you’ve got a few solar panels lying around, or even if you want some 120/230 V AC power from a few 12 Volt batteries, you’ll need a power inverter. Sure, you can drop on down to any big box store and pick one of these up, or you can be like [Michael] and build your own (Danish, translation).

[Michael] found himself in the possession of a few halogen light transformers and decided to make use of them by building a DC to AC power inverter. The inverter is fairly simple – just the transformer, a few MOSFETS, and an ATMega0168 for software control that includes a ‘soft start’ feature that prevents power surges on startup.

The circuit is simple enough to etch at home, although a soldermask and a nice insulated enclosure would probably be ideal for this application.

Guitarduino Show And Tell

June 14, 2013 by Mike Szczys 13 Comments

guitarduino-show-and-tell

[Igor Stolarsky] plays in a band called 3’s & Sevens. We’d say he is the Guitarist but since he’s playing this hacked axe we probably should call him the band’s Guitarduinist. Scroll down and listen to the quick demo clip of what he can do with the hardware add-ons, then check out his video explanation of the hardware.

There are several added inputs attached to the guitar itself. The most obvious is the set of colored buttons which are a shield riding on the Arduino board itself. This attaches to his computer via a USB cable where it is controlling his MaxMSP patches. They’re out of the way and act as something of a sample looper which he can then play along with. But look at the guitar body under his strumming hand and you’ll also see a few grey patches. These, along with one long strip on the back of the neck, are pressure sensors which he actuates while playing. The result is a level of seamless integration we don’t remember seeing before. Now he just needs to move the prototype to a wireless system and he’ll be set.

If you don’t have the skills to shred like [Igor] perhaps an automatic chording device will give you a leg up.

Continue reading “Guitarduino Show And Tell” →

Loading Atari Games From An SD Card

June 12, 2013 by Brian Benchoff 16 Comments

Atari

They’re not a 2600, but the Atari 400, 800 and 1200 are awesome computers in their own right. With only BASIC built in to the ROM, they’re not especially useful or fun, as [Jeroen] found out when he acquired an 800 with a broken tape drive. There are options that allow you to load emulator files from a PC, but [Jeroen] wanted something more compact. He came up with a way to load games and apps off an SD card using a simple microcontroller.

The 400, 800, and 1200 each have a port that allows the computer to talk to printers, modems, disk drives, and load games. There are already a few circuits around that connect the SIO port to a computer so games can be loaded, but [Jeroen] wanted a more compact and portable solution for his 800.

What he came up with is actually pretty simple; just an Arduino, SD card, and an LCD display that allows him to browse the directory on the SD card and load it into the 800’s memory.

A lot of folks over on the Atariage forums are really impressed with [Jeroen]’s work, and would like to get their hands on one of these boards themselves. The project isn’t done just yet – [Jeroen] still needs to make a case for his device – but hopefully he’ll be spinning a few boards up in the coming months.

You can see a pair of videos of the device in action below.

Continue reading “Loading Atari Games From An SD Card” →

Giving An RC Tank A Fire Control Computer

June 11, 2013 by Brian Benchoff 29 Comments

tank

[Vincent] plays around with remote control tanks, and even though his current model is a WWII-era armor piece, he’d still like modern accoutrements such as a fire control computer and laser sighting for his main gun. His latest project did just that (French, Google translation) with the help of an Arduino, a few modifications to the receiver, and an IR rangefinder.

The stock RC tank includes servos to move the turret and the requisite electronics to fire an Airsoft gun. The precision of the mechanical movements inside the turret weren’t very precise, though, so [Vincent] had to gear down the servos to turn large movements into slight adjustments. After that, he installed an IR rangefinder and laser diode onto the barrel that allowed the gun to sight a target and read its distance.

After some experimentation with the rangefinder and laser, [Vincent] plotted data from firing a few BBs at a whole bunch of distances and targets. The graph came out fairly linear, and after plugging this into a graphing calculator, he was able to find an equation that took into account the distance and angle so the Arduino-powered fire control computer would hit its mark.

The accuracy of the gun is very impressive, all things considered. [Vincent] is able to accurately fire BBs downrange and hit an 8×12 cm target at five meters. You can check out that action below.

Continue reading “Giving An RC Tank A Fire Control Computer” →

Echolocation Pinpoints Where A Gunshot Came From

June 9, 2013 by Mike Szczys 50 Comments

echolocating-gunshots

[Kripthor] suspected that hunters were getting too near his house. When thinking of a way to quantify this belief he set out to build a triangulation system based on the sound of gunshots. The theory behind it is acoustic location, which is a specialized type echolocation.

The most common example of echolocation is in Bats, who emit ultrasonic noise and listen for its return (echo) to judge the location of objects. [Kripthor] doesn’t need to generate the sound himself, he just needs to pick it up at different points. The time difference from the three samples can be used to triangulate coordinates as seen in the image above.

He first tried using a PC sound card to collect the samples. The stereo input only provides two channels so he tinkered around with a 555-based multiplexing circuit to sample from three. The circuit noise created was just too great so he transitioned to using an Arduino. The ADC samples from each microphone via an NPN transistor which is used as a simple amplifier.

This brings to mind a homebrew sonar hack from way back.