The 30th Anniversary Macintosh

February 5, 2014 by 17 Comments

It’s been just over thirty years since the original Macintosh was released, and [hudson] over at NYC Resistor thought it would be a good time to put some old hardware to use. He had found an all-in-one Mac SE “on the side of a road” a while ago (where exactly are these roads, we wonder), and the recent diamond anniversary for the original mac platform convinced him to do some major hardware hacking.

Inspired by a six-year-old project from a NYC Resistor founder aptly named the 24th anniversary Mac, [hudson] decided to replace the old hardware with more powerful components – in this case, a BeagleBone Black. Unlike the earlier build, though, the original CRT would be salvaged; the analog board on the Mac SE has pins for video, hsync, vsync, and power.

To get a picture on the old CRT, [hudson] needed to write a software video card that used the BeagleBone’s PRU. The CRT isn’t exactly “modern” tech, and everything must be clocked at exactly 60.1 Hz lest the CRT emit a terrible buzzing sound.

With a software video card written for the old CRT, the BeagleBone becomes the new brains of this beige box. It runs all the classic Linux GUI apps including XEyes and XScreenSaver, although flying toasters might be out of the question. He also managed to load up the Hackaday retro site with xterm, making this one of the best ways to make an old Mac SE useful.

Cassapa: Augmented Pool

February 5, 2014 by 48 Comments

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No good at pool? Never fear, Cassapa is here! [Alex Porto] has created an augmented reality system for playing pool, and it means almost anyone can make those cool trick shots!

Ca-what? Cassapa (“caçapa”) is a Portuguese word for pool table pocket. The software works by placing a webcam directly above the pool table for image recognition. Dedicated software interprets the image and identifies the position of the holes, borders, balls and the cue which can then be used to calculate game physics. A projector then projects the forecast physics and allows you to make tiny adjustments — updated in real-time — to make the perfect shot.

Unfortunately, having a big projector shining down on your pool table won’t exactly make anyone believe you’re actually good at pool. Although if you could combine this with Google Glass or any other vision augmenting goggles… that would be pretty cool. Well, you’d still be terribly dishonest and a cheater — but anyway, take a look at the video after the break.

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Software-Controlled Per-Port Power Switching For USB Hubs

February 5, 2014 by 34 Comments

[Befi] wanted to add a second stage backup disk to his ODROID embedded-board server, which typically draws ~1.5W at idle. After adding the disk, he saw power consumption increase by 2W when the new disk wasn’t spinning. He thought about using one of those USB hubs with the adorable little rocker switches for each port and replacing them with transistors, but that was going to be messy. After some poking around in the USB standard, he found that most support per-port power switching (PPPS), and set about to hack a USB hub to enable software-controlled per-port switching.

[Befi]’s NEC hub uses a uPD720112 chip which supports PPPS according to the datasheet. After tying the configuration pin labeled GANG_B to +3.3V, the hub declared itself PPPS-compatible. Of course, the manufacturer saved a penny or two by omitting the  individual switches, so [Befi] added an open-drain NMOS to each port. He is using this program to switch the port on and off and made the switching transparent with autofs. [Befi]’s current script has the bus ID and device ID of the hub hard-coded, but he intends to update it to find them automatically. This hack saves him 10W on average, which is about €30 ($40) per year.

If your hub is under powered, you could try adding an external power supply.

Hidden Pantry Compartment Opens With A Puzzle!

February 5, 2014 by 20 Comments

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What’s the number one thing kids always dream about for when they have their own house someday? Hidden passages? Revolving bookcases? Closets that lead to Narnia? Secret compartments? Well, [TracRat] has lived out at least one of those dreams by making his very own Myst inspired hidden pantry compartment!

His pantry is located under the stairs and to make use of the awkward space, he decided to build a wine rack. He still had a lot of unused space so he decided to take it a step further. He’s built a wooden puzzle combination lock consisting of four colored knobs that slide back and forth in grooves. When the correct combination is made, pressing on the square symbol at the top rolls the entire wine rack backwards, exposing a secret side cabinet. It’s an absolutely gorgeous piece of woodwork and we’re totally impressed by the perfect execution of it.

Do you love Myst too? Check out this awesome Myst inspired Myst(ery) box [Michael] made for his girlfriend’s birthday! Or how about a leather-bound Myst book that lets you play Myst on a computer inside of it!

Tic Tac PIC Pack: A Pocket Programmer

February 5, 2014 by 10 Comments

Sure, mint tin housings are great. But you have to defend against shorts, and cutting out holes for ports and buttons is dangerous business. [Daniel] prefers plastic, and he tipped us off about a PICKit2 clone that he designed to fit inside of a tic tac box.

Almost all of the components were salvaged except for the microcontroller and the connectors. He wound his own inductor using the ferrite core from a CFL. [Daniel] had to make a few improvisations for this project. He didn’t have a 20MHz crystal, so he used a 12MHz crystal and tweaked the fuse bits after burning the firmware.

To save space on the board, he soldered wires to RESET, VCC, GND, PGD, and PGC to program the firmware and then removed the wires. The only trouble he had with it was more or less easily solved by replacing two transistors.

You may remember that we linked to his USBasp programmer in a mentos container a few months back. We figure [Daniel] must have some pretty fresh breath.

Nimble Dodgebot Is Super Skittish

February 4, 2014 by 10 Comments

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For one of [Aron’s] recent robotics modules at college he was tasked with building a small robot. He decided to make project Dodgebot, a cute and extremely quick robot that won’t run into things!

The body is made of perforated steel and supports the motor boxes with wheels (stolen from a toy perhaps?), two IR sensors, and the tidy protoboard on top to contain the electronics — seriously check out the wiring on it!

To control it he’s using an 18-pin dsPIC30F3012 and a SN754410NE driver. The robot works by detecting different states based on the distance measurements from each sensor, and then varying the output to each motor. It’s extremely quick and quite fun to watch as it seems to dodge everything in its path! See for yourself, after the break. 

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WS2811 SPI Driver Using One Transistor And Passives

February 4, 2014 by 6 Comments

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We love the WS28xx projects because even if we never plan to use them, the signal timing is like the most addictive puzzle game ever. For instance, check out this WS2811A driver which uses hardware SPI to generate the signals.

The WS28xx offerings place a microcontroller inside an RGB LED, allowing them to be individually addressed in very long chains or large matrices (still a chain but different layout). But the timing scheme used to address them doesn’t play well with traditionally available microcontroller peripherals. [Brett] had been intrigued by some of the attempts to bend hardware SPI to the will of the WS2811 — notably [Cunning_Fellow’s] work featured in this post. He took it a great step forward by simplifying the driver to just one transistor, three resistors, and a capacitor.

Click through the link above for his step-by-step description of how the circuit works (it’s not worth re-explaining here as he does a very concise job himself). The oscilloscope above shows the SPI signal on top and the resulting timing signal below. You will notice the edges aren’t very clean, which requires the first pixel to be very close to the driver or risk further degradation. But, since the WS28xx drivers feature a repeater which cleans up signals like this, it’s smooth sailing after the first pixel.