An Overkill Network Adapter For Retrocomputers

May 28, 2013 by 49 Comments

amiga

If you want to get an old Apple, Commodore 64, Amiga, or any other retrocomputer up on the Internet, this is for you. [Stian] had an Amiga 500 lying around and wanted to put it on a network. The A500 isn’t expandable, so he needed to look at some sort of adapter to put it on a network. The solution came to him in the form of a Raspberry Pi, a null modem cable, and a few bits of software.

To connect his Amiga to his network, [Stian] made a small serial converter board for his Raspi that breaks out the Tx and Rx pins on the Pi to a 9-pin serial port. With the physical connection to the Pi made, the only thing left to do was to get some software for the Amiga, namely AmiTCP and PPP. It’s not exactly a fast network connection, but this build allows [Stian] to connect to WiFi networks with ancient hardware.

One interesting aspect of [Stian]’s build is the fact it’s completely transferable to other retrocomputers – everything from old S-100 bus computers to classic macs, apples, and pretty much anything else with a serial port that supports PPP. Even with the expense of a Raspberry Pi, it’s much cheaper than absurdly expensive second-hand SCSI to Ethernet controllers and other tomfoolery.

Shocking Your Brain And Making Yourself Smarter

May 28, 2013 by 52 Comments

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Transcranial Direct Current Stimulation – or tDCS – is the technique of applying electrodes to the skull and running a small but perceptible current through them. It’s not much current – usually on the order of 1 or 2 mA, but the effect of either increasing or decreasing neural activity has led to some interesting studies. [Theo] over on Instructables wrote a tutorial for making his own tDCS suppy that will supply 2 mA to electrodes placed on the skull for everyone to experiment with.

The basic idea behind tDCS is to put the positive electrode over the part of the brain to be excited or the negative electrode over the part of the brain to be inhibited. This is a well-studied technique that can be used to improve mathematical ability. It’s not electroshock therapy (although that is a valid treatment for depression and schizophrenia) in that a seizure is induced; tDCS just applies a small current to specific areas of the brain to excite or inhibit function.

[Theo]’s device is a simple circuit made of a transistor, resistors, and a few diodes to provide about 2 mA to a pair of electrical contacts. With this circuit and a few gel electrode pads for your head, you too can experiment with direct current stimulation of your brain.

Of course we need to warn you about putting electricity into your head. In any event, here’s a quadcopter / stun gun mashup we made. Don’t do that, either. You might get a takedown request.

Etch Your Own CPLD Development Board

May 28, 2013 by 16 Comments

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Ever wanted to make the jump from microcontrollers to logic chips? Although not technically the same thing we consider FPGA and CPLD devices to be in similar categories. Like FPGAs, Complex Programmable Logic Devices let you build hardware inside of a chip. And if you’ve got the knack for etching circuit boards you can now build your own CPLD development module. Long-time Hackaday readers will remember our own offering in this area.

Our years of microcontroller experience have taught us a mantra: if it doesn’t work it’s a hardware problem. We have a knack for wasting hours trying to figure out why our code doesn’t work. The majority of the time it’s a hardware issue. And this is why you might not want to design your own dev tools when just starting out. But one thing this guide has going for it is incremental testing. After etching and inspecting the board, it is populated in stages. There is test code available for each stage that will help verify that the hardware is working as expected.

The CPLD is programmed using that 10-pin header. If you don’t have a programmer you can build your own that uses a parallel port. Included on the board is an ATtiny2313 which is a nice touch as it can simulate all kinds of different hardware to test with your VHDL code. There is also a row of LEDs, a set of DIP switches, and a few breakout headers to boot.

Blood Glucose Monitor Data Pushed To Smart Watch

May 27, 2013 by 39 Comments

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[Don] uses a Continuous Glucose Monitor to stay on top of his diabetes. It means carrying around an expensive and fragile device which acts as the readout. He’s an active guy and doesn’t want to destroy the thing while dirt biking or kick boxing so he’s been trying to use a TI Chronos smart watch as a display alternative.

As you can see he has already made some headway. This image shows the watch displaying data from the device. Unfortunately he’s depending on a PC to interface with the CGM display, then pushing it to the watch. He may try moving to a Raspberry Pi to help make this more mobile. This way the sensitive hardware could be tucked safely in a case inside a backpack while the watch shows his current glucose levels. We’d also love to see an embedded solution that would emulate the communications the PC is using to harvest the data. If you’ve got any suggestions in this area we’re sure that [Don] would appreciate the help.

WS2811 Can Be Addressed At 800kHz Using A 8MHz Clock

May 27, 2013 by 35 Comments

ws2811-running-at-8mhz

Timing is everything and that’s why most communication protocols require a very accurate clock source. The WS2811 LED strip controllers are no different. But [Danny] figured out a way to drive them reliably with an 8MHz clock source.

The WS2811 has become one of the most popular controllers for RGB pixels and strips alike. We’ve seen several hacks used to address them, including the 16MHz AVR technique that inspired [Danny] to take on this project. He planned to use that library but the 25-day shipping time for a 16MHz crystal drove home to invent a way to use the internal oscillator instead.

The gist of the hack is that he wrote assembly code to handle pairs of binary bit values. With a code block for each of the four possible combinations in hand he had to find a way to craft the conditional jumps to preserve accurate timing. After hitting the wall trying to solve this puzzle by hand he wrote a C++ program to solve it for home. The proof is in this video which shows one chip driving multiple Larson scanners on a single strip.

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Adding Night Vision To The Raspberry Pi Camera

May 27, 2013 by 26 Comments

After months of promises, the Raspberry Pi camera is finally heading out to hackers and makers across the world. Of course the first build with the Pi cam to grace the pages of Hackaday would be removing the IR filter, and it just so happens [Gary] and his crew at the Reading hackerspace are the first to do just that.

As [Gary] shows in his video, the process of removing the Pi cam’s IR filter is extremely fiddly.  Getting the filter out of the camera involves removing the sensor, gently cutting it open with a scalpel, and finally gluing the whole thing back together with a tiny bit of superglue. Not for the faint of heart, and certainly not for anyone without a halfway decent bench microscope.

If you’re looking for a Raspberry Pi-powered security camera, game camera, or something for an astronomy application, this is the way to make it happen. You might want to be careful when removing the IR filter; [Gary] broke one camera on their first attempt. They got it to work, though, and the picture quality looks pretty good, as seen in the videos below.

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Book Review: The Good Life Lab

May 27, 2013 by 12 Comments

the-good-life-lab

Stop whatever you’re doing and get this book. I’ve just finished reading it and I have to say that [Wendy] and [Mikey] could easily be the poster children for modern day hacking, and this book could be the manual for a life built on hacking.

When I visited [Wendy] and [Mikey] last year I was blown away.  Their little homestead was a veritable smorgasbord of hacks. Everywhere I looked, things were cobbled together, modified, repaired, and improved. There wasn’t a single piece of their lives that wasn’t somehow improved by their efforts to play an active role in their own living.

That sounds a bit cheesy I know. We all play an active role in our lives right? Sure. But what they have done is created a hacker’s homestead. My projects tend to live on my workbench, occasionally poking into my daily life, but they went were there was virtually nothing and hacked together everything they found they needed.  Their life is their workbench.

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