Internet-Enabling A Lamp With The Raspberry Pi

December 11, 2013 by Phillip Ryals 30 Comments

[Jack] sent in his writeup for internet enabling a home lamp. While we will certainly have some comments saying this is too simple, it does a great job of breaking things down to the basics. For those that aren’t confident in their electronic skills, this is an easy hack to a commercial device that greatly expands it’s capabilities. [Jack] started with a cheap wireless outlet controller. By opening the remote and wiring each switch to a 2N222A transistor, you can very easily control the remote from the GPIO pins on the Raspberry Pi. In [Jack’s] case, he set up a web page using Flask that allows quick on/off control.

Of course, this method can be used in any number of instances where you have a wireless controller, from small lamps to garage doors. Given it’s simplicity, anyone can do it with even basic skills. If you’re a beginner who’s been itching to do some home automation, follow [Jack’s] writeup and check an item off your todo list!

VFD And Nixie Clock Twofer

December 10, 2013 by Brian Benchoff 18 Comments

Sometimes the stars align and we get two somewhat similar builds hitting the Hackaday tip line at the same time. Recently, the build of note was clocks using some sort of display tube, so here we go.

First up is [Pyrofer]’s VFD network time clock (pic, above). The build started as a vacuum flourescent display tube he salvaged from an old fruit machine – whatever that is. The VFD was a 16 character, 14 segment display, all controlled via serial input.

The main control board is, of course, an Arduino with a WizNet 5100 Ethernet board. The clock connects to the Internet via DHCP so there’s no need to set an IP address. Once connected, the clock sets itself via network time and displays the current date, time, and temperature provided by a Dallas 1-wire temperature probe.

Next up is [Andrew]’s beautiful Nixie clock with enough LEDs to satiate the desires of even the most discerning technophile. The board is based on a PIC microcontroller with two switching power supplies – one for the 170VDC for the Nixies, and 5V for the rest of the board.

A battery backed DS1307 is the real-time clock for this board, and two MCP23017 I/O expanders are used to run the old-school Nixie drivers

All this is pretty standard for a Nixie clock build, if a little excessive. It wasn’t enough for [Andrew], though: he used the USB support on his PIC to throw a USB port on his board and wrote an awesome bit of software for his PC to set the time, upload new firmware, and set the color fade and speed. With this many LEDs, it’s not something you want in your bedroom with all the lights on full blast, so he implemented a ‘sleep’ mode to turn off most of the lights and all the Nixie tubes. It’s a great piece of work that could easily be successfully funded on Kickstarter.

8-Track Tapes As A Storage Medium

December 10, 2013 by Brian Benchoff 42 Comments

OLYMPUS DIGITAL CAMERA

Before [Woz] created the elegant Disk II interface for the Apple II, and before Commodore brute-forced the creation of the C64 5 1/4″ drive, just about every home computer used cassette tapes for storage. Cassette tapes, mind you, not 8-track tapes. [Alec] thought this was a gross oversight of late 1970s engineers, so he built a 8-track tape drive.

This actually isn’t the first instance of using 8-tracks to store data on a computer. The Compucolor 8001 had a dual external 8-track drive, and the Exidy Sorcerer had a tape drive built in to the ‘the keyboard is the computer’ form factor. It should be noted that nearly no one has heard about these two computers – the Compucolor sold about 25 units, for example – so we’ll just let that be a testament to the success of 8-track tape drives.

[Alec] installed an 8-track drive inside an old external SCSI hard drive enclosure. Inside is an Arduino that controls the track select, tape insertion and end of tape signals. Data is encoded with DTMF with an FSK encoding, just like the proper cassette data tapes of the early days.

On the computer side of things, [Alec] is using a simple UNIX-style, pipe-based I/O. By encoding four bits on each track, he’s able to put an entire byte on two stereo tracks. The read/write speed is terribly slow – from the video after the break, we’re assuming [Alec] is running his tape drive right around 100 bits/second – much slower than actually typing in data. This is probably a problem with the 40-year-old 8-track tape he’s using, but as a proof of concept it’s not too bad.

Continue reading “8-Track Tapes As A Storage Medium” →

Guest Post: The Real Story Of Hacking Together The Commodore C128

December 9, 2013 by Bil Herd 148 Comments

The most popular computer ever sold to-date, the Commodore C-64, sold 27 Million units total back in the 1980’s. Little is left to show of those times, the 8-bit “retro” years when a young long-haired self-taught engineer could, through sheer chance and a fair amount of determination, sit down and design a computer from scratch using a mechanical pencil, a pile of data books, and a lot of paper.

Before Apple there was Commodore — Behind the C-128 from a 1985 Ad

My name is Bil Herd and I was that long-haired, self-educated kid who lived and dreamed electronics and, with the passion of youth, found himself designing the Commodore C-128, the last of the 8-bit computers which somehow was able to include many firsts for home computing. The team I worked with had an opportunity to slam out one last 8 bit computer, providing we accepted the fact that whatever we did had to be completed in 5 months… in time for the 1985 Consumer Electronics Show (CES) in Las Vegas.

We (Commodore) could do what no other computer company of the day could easily do; we made our own Integrated Circuits (ICs) and we owned the two powerhouse ICs of the day; the 6502 microprocessor and the VIC Video Display IC. This strength would result in a powerful computer but at a cost; the custom IC’s for the C-128 would not be ready for at least 3 of the 5 months, and in the case of one IC, it would actually be tricked into working in spite of itself.

Continue reading “Guest Post: The Real Story Of Hacking Together The Commodore C128” →

Logic Analyzers And X11

December 5, 2013 by Brian Benchoff 18 Comments

logic

[Andrew] recently scored an awesome HP 1670A Deep Memory Logic Analyzer, lucky dog. Even though this machine was built in 1992, it was a top of the line device back in the day and had a few very interesting features. This logic analyzer also had a few networking ports implementing FTP, NFS, TCP/IP, and the X11 protocols over a 10Base2 (“thinlan”) and 10BaseT (“ethertwist” seriously, that’s what’s in the manual) connections. The X11 protocol interested [Andrew] so he set this logic analyzer up so he could use it via his Linux box.

X Windows is simply a way to display GUI interfaces over a network. While today we usually only see X Windows apps confined to the desktop, in the bad old days of *NIXes you had to pay for, running a GUI app over a network was considered the wave of the future. The Internet replaced this idea with a palimpsest of JavaScript, but we digress…

[Andrew]’s new toy didn’t support DHCP, so after inputting the IP address manually, he checked the host file – still the same after twenty years – and connected with his Linux Mint box. The result is a remote control panel for the ‘ol girl in a garish color scheme that violates all modern sensibilities.

A 555-Based, Two-Channel Remote Control Circuit

December 4, 2013 by Phillip Ryals 21 Comments

[fahadshihab], a young tinkerer, shared his circuit design for a simple remote control using 555 timers. Using a 555 calculator, he designed a clock circuit that would run at 11.99 Hz. Two transistors are connected to inputs (presumably button switches). One sends the plain clock signal, and one sends the inverted clock signal. A matching circuit at the other end will separate the channels. All it requires is connecting the two circuits in order to synchronize them. It would be easy enough to interface this with an oscillator, an IR LED, or a laser for long-range control.

The great thing about this circuit is its simplicity. It’s often so easy to throw a microcontroller into the mix, that we forget how effective a setup like this can be. It could also be a great starter circuit for a kid’s workshop, demonstrating basic circuits, timers, and even a NOT gate. Of course, it would be a good refresher for those without a lot of circuit knowledge too. Once you’ve mastered this, perhaps an AM transmitter is next?

Crafting A Liquid Crystal Display

December 2, 2013 by Brian Benchoff 17 Comments

Throughout the 1960s, the management at RCA thought LCD ~~displays~~ were too difficult to commercialize and sent their engineers and researchers involved in LCDs off into the hinterlands. After watching [Ben Krasnow]’s efforts to build a liquid crystal display, we can easily see why the suits thought what they did. It’s an amazing engineering feat.

Before building his own version of an LCD (seen above in action), he goes through the mechanics of how LCDs operate. Light enters the display, goes through a polarizer, and is twisted by a liquid crystal material. The first successful LCDs used two types of liquid crystals – chiral and nematic. By combining these two types of molecules in the right proportion, the display can ‘twist’ the polarized light exactly 90 degrees so it is blocked by the second piece of polarizing film in the display.

Besides getting the right crystals and engineering processes, another major hurdle for the development of LCDs ~~displays~~ is transparent electrically conductive traces. [Ben], along with every other LCD manufacturer, uses a thin layer of indium tin oxide, or ITO. By embedding these clear electrodes in the display, segments can be built up, like the seven segment displays of a calculator or a bunch of tiny dots as found in a TV or computer monitor.

In the end, [Ben] was able to build an extremely simple single-segment LCD ~~display~~ out of a pair of microscope slides. It does modulate light, just barely. With a lot of work it could be made in to a calculator type display but for now it’s an awesome demonstration of how LCDs actually work. Continue reading “Crafting A Liquid Crystal Display” →