VCF East: The Swyft Card

April 6, 2014 by 31 Comments

Ninety five percent of the population will say Apple computers is the brainchild of [Steve Jobs]. The other five percent will be right, but what nearly no one knows is that the Macintosh project was originally conceived by [Jef Raskin]. He holds the honor of turning the Mac into an, ‘information appliance’ and being one of the first people to seriously consider how millions of people would interact with computers.

The Mac wasn’t [Jef]’s first project at Apple, though. Before the Mac project he was working on something called Swyft – an easy to use command line system that was first implemented as a firmware card for the Apple IIe. [Mike Willegal] was kind enough to bring one of these Swyft cards to the Vintage Computer Fest this weekend, and did a demo of it for us.

The basic idea behind the Swyft card was to have an integrated word processor, calculator, and access to Applesoft Basic. Holding down a ‘leap’ key – in the case of the Apple IIe add-on, the open apple key – allowed the user to search for text and perform operations on any result. It’s odd, but it just makes sense in some strange way.

[Mike] is doing a build class at the VCF today where anyone attending can build their own Swyft card. He also has instructions for building your own, should you want to experiment with one of the ‘could have beens’ of user interface design.

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CPLD Tutorial: Learn Programmable Logic The Easy Way

April 6, 2014 by 16 Comments

The guys over at hackshed have been busy. [Carl] is making programmable logic design easy with an 8 part CPLD tutorial. (March 2018: Link dead.  Try the Wayback Machine.) Programmable logic devices are one of the most versatile hardware building blocks available to hackers. They also can have a steep learning curve. Cheap Field Programmable Gate Arrays (FPGA) are plentiful, but can have intricate power requirements. Most modern programmable logic designs are created in a Hardware Description Language (HDL) such as VHDL or Verilog. Now you’ve got a new type of device, a new language, an entirely new programming paradigm, and a complex IDE to learn all at once. It’s no wonder FPGAs have sent more than one beginner running for the hills.

The tutorial cuts the learning curve down in several ways. [Carl] is using Complex Programmable Logic Devices (CPLD). At the 40,000 foot level, CPLDs and FPGAs do the same thing – they act as re-configurable logic. FPGAs generally do not store their configuration – it has to be loaded from an external FLASH, EEPROM, or connected processor. CPLDs do store their configuration, so they’re ready as soon as they power up. As a general rule, FPGAs contain more configurable logic than CPLDs. This allows for larger designs to be instantiated with FPGAs. Don’t knock CPLDs though. CPLDs have plenty of room for big designs, like generating VGA signals.

[Carl] also is designing with schematic capture in his tutorial. With the schematic capture method, digital logic schematics are drawn just as they would be in Eagle or KiCad. This is generally considered an “old school” method of design capture. A few lines of VHDL or Verilog code can replace some rather complex schematics. [Carl’s] simple designs don’t need that sort of power though. Going the schematic capture route eliminates the need to learn VHDL or Verilog.

[Carl’s] tutorial starts with installing Altera’s Quartus II software. He then takes the student through the “hardware hello world” – blinking an LED.  By the time the tutorial is done, the user will learn how to create a 4 bit adder and a 4 bit subtractor. With all that under your belt, you’re ready to jump into big designs – like building a retrocomputer.

[Image via Wikimedia Commons]

Creative Continuity Tester Made For A Few Bucks

April 6, 2014 by 13 Comments

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No multi-meter? For troubleshooting most household things, a continuity tester is extremely handy. And as it turns out, you can make your own from the dollar store for next to nothing.

[Carlyn] shows us how to make two different styles of continuity testers — a light up version using a bicycle light, or a buzzer version using one of those cheap window alarms. The leads are made of 1/8″ audio cables — and everything for both these testers cost less than $5 from their local dollar store. It’s a very simple build process that you can probably figure out just from this one photo, but [Carlyn] has also taken pictures of every step along the way.

Compared to building one of these out of components from Radio Shack, this method is much more MacGyver, and cheap! Hooray for taking advantage of mass produced consumer products!

Not functional enough? How about building a talking multimeter instead? No? Have you ever wanted two multi-meters in one? Say hello to the Mooshimeter!

University Attempts To Break 3D Printing World Record

April 5, 2014 by 83 Comments

lulz

LeTourneau University attempted to set a 3D printing Guinness World Record yesterday. They had 50 3D printers print the same thing at the same time. Impressive? Kind of, but not really.

LulzBot — our favorite 3D printer company — saw this and thought “that’s cute — we run over 50 printers a day on a normal basis!”. So just for lulz, they decided to film a little counter-record video featuring 109 LulzBot 3D printers running simultaneously.

To be honest, we kinda feel sorry for LeTourneau University — but it looks like LulzBot really takes the cake here. The university has a really cool policy for their engineering students though — all incoming freshmen students are required to build their own 3D printer for school. Whoa! To be honest it is a really cool way to force you to get out of your comfort zone and learn a bit about several different engineering disciplines.

To follow along the discussion and status of the record, a thread is going on over at 3Dprintboard.com. Stick around to see the video of LulzBot’s drool worthy server racks filled with identical printers.

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Super Mario On A Human-Machine-Interface!

April 5, 2014 by 3 Comments

super mario

Getting Super Mario to work on your TI-83 calculator is almost a rite of passage for young geeks, so we really liked this project where [Chad Boughton] managed to get it running on a PLC’s HMI screen instead!

He’s using a Danfoss DP600LX microcontroller with an HMI display along with a CAN bus joystick. This kind of equipment is typically used to control hydraulic systems, as well as display sensor data — [Chad] was curious to see if he could do animation with it as well — it looks like he’s succeeded! The funny thing is we’ve seen those “joysticks” before and it’s cool to see them used for something like this — like [Chad] said, they’re normally used for actuating hydraulic and pneumatic cylinders.

Stick around after the break to see Mario eat some mushrooms.

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Gesture Recognition Using Ultrasound

April 5, 2014 by 27 Comments

SAMSUNG

You’d be hard pressed to find a public restroom that wasn’t packed full of hands free technology these days. From the toilets to the sinks and paper towel dispensers, hands free tech is everywhere in modern public restrooms.

The idea is to cut down on the spread of germs.  However, as we all know too well, this technology is not perfect. We’ve all gone from sink to sink in search of one that actually worked. Most of us have waved our hands wildly in the air to get a paper towel dispenser to dispense, creating new kung-fu moves in the process. IR simply has its limitations.

What if there was a better way? Check out [Ackerley] and [Lydia’s] work on gesture recognition using ultrasound. Such technology is cheap and could easily be implemented in countless applications where hands free control of our world is desired. Indeed, the free market has already been developing this technology for use in smart phones and tablets.

Where a video camera will use upwards of 1 watt of power to record video, an ultrasound device will use only micro watts. IR can still be used to detect gestures, as in this gesture based security lock, but lacks the resolution that can be obtained by ultrasound.  So let us delve deep into the details of [Ackerley] and [Lydia’s] ultrasound version of a gesture recognizer, so that we might understand just how it all works, and you too can implement your own ultrasound gesture recognition system.

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Open Source Power Line Communication

April 5, 2014 by 40 Comments

Power Line Communication Filtering

 

Since we all have wires running throughout our houses to provide mains power, there’s a number of devices that piggyback on mains lines for communication. For his thesis project, [Haris Andrianakis] developed his own power line communication system.

The basic principle of the system is to inject a signal onto the power lines at a much higher frequency than the 50 or 60 Hz of the AC power itself. Using both active and passive filters, the signal can be separated from the AC power and decoded. This system uses frequency-shift keying to encode data. This part is done by a ST7540 modem that’s designed for power line applications. The modem is controlled over SPI by an ATmega168 microcontroller.

[Haris]’ write up goes into detail about some of the challenges he faced, and how to protect the device from the high voltages present. The final result is a remote display for a weigh scale, which communicates over the power line. Schematics, PCB layout, and software are all available.