Commodore 1530 Datasette gets a Digital Counter

com-tape

Ah, the humble Commodore 1530 Datasette drive. It never enjoyed much popularity in the USA, but it was the standard for quite some time in Europe. [DerSchatten13] still uses and loves his 1530. When a co-worker showed him some 7-segment bubble LEDs, he knew what he had to do. Thus the 1530 digital counter (translated) was born.

[DerSchatten13] started out by building his design on a breadboard. He used every I/O pin on an ATtiny2313 to implement his circuit. Tape motion is detected by a home-made rotary encoder connected to the original mechanical counter’s belt drive. To keep the pin count down, [DerSchatten13] multiplexed the LEDs on the display.

Now came the hard part, tearing into the 1530 and removing the mechanical counter. [DerSchatten13] glued in some standoffs to hold the new PCB. After rebuilding the circuit on a piece of perfboard, he installed the new parts. The final result looks great on the inside. From the outside, one would be hard pressed to tell the digital counter wasn’t original equipment.

Operation of the digital counter is identical to the analog unit – with one exception. The clear button now serves double duty. Pressing and holding it saves the current count. Save mode is indicated by turning on the decimal point. If the user rewinds the tape, the counter will stop the motor when the saved count is reached. Cueing up that saved program just got a heck of a lot easier!

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Finding And Repairing Microscopes From The Trash

scope We’re not quite sure where [Andy] hangs out, but he recently found a pile of broken microscopes in a dumpster. They’re old and obsolete microscopes made for biological specimens and not inspecting surface mount devices and electronic components, but the quality of the optics is outstanding and hey, free microscope.

There was a problem with these old scopes – the bulb used to illuminate specimens was made out of pure unobtainium, meaning [Andy] would have to rig up his own fix. The easiest way to do that? Some LEDs made for car headlights, of course.

The maker of these scopes did produce a few for export to be used in rural areas all across the globe. These models had a 12 Volt input to allow the use of a car battery to light the bulb. A LED headlight also runs off 12 Volts, so it was easy for [Andy] to choose a light source for this repair.

A little bit of dremeling later, and [Andy] had the new bulb in place. An off the shelf PWM controller can vary the brightness of the LED, controlled with the original Bakelite knob. The completed scope can easily inspect human hairs, the dust mites, blood cells, and just about anything down to the limits of optical microscopy. Future plans for this microscope might include another project on hackaday.io, a stage automator that will allow the imaging of huge fields at very high magnification – not bad for something pulled out of the trash.

Teaching the Word Clock Some New Tricks

wordclock2014

[Joakim] has built a clock that spells out the time in words. Wait a second – word clock, what is this, 2009? Word clocks are one of those projects that have become timeless. When we see a build that stands out, we make sure to write it up. [Joakim's] clock is special for a number of reasons. The time is spelled out in Norwegian, and since the clock is a birthday gift for [Daniel], [Joakim] added the his full name to the clock’s repertoire.

One of the hard parts of word clock design is controlling light spill. [Joakim] used a simple 3D printed frame to box each LED in. This keeps the spill under control and makes everything easier to read. The RGB LED’s [Joakim] used are also a bit different from the norm. Rather than the WS2812 Neopixel, [Joakim] used LPD8806 LED strips. On the controller side [Joakim] may have gone a bit overboard in his choice of an Arduino Yun, but he does put the ATmega328 and Embedded Linux machine to good use.

The real magic happens at boot. [Daniel's] name lights up in red, with various letters going green as each step completes. A green ‘D’ indicates an IP address was obtained from the router’s DHCP server. ‘N’ switches to green when four NTP servers have been contacted, and the Linux processor is reasonably sure it has the correct time. The last letter to change will be the ‘E’, which reports ambient light.

[Joakim] added a web interface to trigger his new features, such as a rainbow color palette, or the ability to show minutes by changing the color of the letters K,L,O,K. The final result is a slick package, which definitely brings a 2009 era design up to 2014 standards!

18-Channel PWM Aquarium Lights Provide Habitat-Like Life for Fish

Aquarium with variable LEDs

Whether you want to keep your fish happy or just need a good light show, this aquarium light fits the bill. It is the second iteration, but [William] calls it v1. That’s because v0 — which used a few loops of LED strips — never really met his requirements.

This build uses just six LEDs, each a 30 Watt RGB monster! To source about 350 mA for each, and to control brightness with 18-channels of pulse width modulation, he had to plan very carefully. This meant a proper aluminum project box and a beefy, fan-cooled power supply.

The driver board is his own design, and he etched a huge board to hold all of the components. Everything is driven by an Arduino Mega, which has 16 hardware PWM channels; two short of what he needed. Because of this he had to spend a bit of time figuring out how best to bit-bang the signals. But he’s putting them to good use, with fish-pleasing modes like “sunset” or the “passing rainbow” pattern which is shown in the image above.

If you need something a little less traditional why not house your fish in a computer case, complete with LED marquee for displaying data.

DIY Keyboard Backlighting Takes Forever, Worth It

LED Keyboard with Custom Lights

Want a back-lit keyboard? Make one yourself. Though you may not want to after seeing this build by [prodigydoo], who devoted 40 hours to upgrade his mechanical keyboard with a smattering of shiny.

No eye rolling just yet, though, because [prodigydoo's] work is a monument to meticulous craftsmanship and dedication. So what if he accidentally dropped the keyboard’s PCB and cracked it? He patched that up with a few wires in true hacker-problem-solving fashion and no one will ever know.

With the electronics “safely” removed, [prodigydoo] set about desoldering every single key switch, then carefully detaching and disassembling the Cherry MX Blues. He then inserted an LED into each switch’s backplate, reassembled them, mounted the keys back on the board, then added some current-limiting resistors and heat shrink to the circuit. [prodigydoo] cut a few necessary holes for a power switch, state indicator LEDs (Caps Lock, etc.) and some under-the-board lighting, then rounded off the build by hooking up a power supply capable of running all the lights.

No microcontroller? No RGBLEDs? We like it anyway, and it seems [prodigydoo] is glad he kept it simple. Go check out the gallery for gritty details, an explanation of the circuit, and more pictures than your family vacation album.

LED Cube in an Elongated Cube be Jammin’

LED cube and drive electronics inside an acrylic case

We get a lot of tips about LED cubes. They’re a great build to explore a lot of different things, from the circuit design, to current source and sink, and of course there’s the firmware. Why don’t we see a million of them on the front page? Well, we have seen a lot, but most of what is sent our way doesn’t exhibit such a clean build. It’s obvious that [Justin] took a lot of pride in his work on this 4x4x4 single-color cube.

Hidden away under one of the protoboards is an Arduino that drives it. A lot of the components were salvaged from the e-waste bin at his University. This includes the 12V AC wall wart he uses to power the device. A bridge rectifier converts to DC, and in addition to powering the LEDs there are a couple of USB charging ports. After the break you can see and hear it in action. The cube pulses to the music but the flip of a switch will disconnect the speaker if you want some peace and quiet to go with the light show.

If you’re looking for a challenge, this 8x8x8 RGB offering is several orders of magnitude harder to pull off… block out a lot of extra time if you do decide to take the plunge. We also heard that [Benchoff] might try to make a cube with some of those through-hole ws2812 pixels.

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POV Display Does it on the Cheap

lowBudgetPOV

[Sholto] hacked together this ultra low-budget spinning display. He calls it a zoetrope, but we think it’s actually an LED based Persistence Of Vision (POV) affair. We’ve seen plenty of POV devices in the past, but this one proves that a hack doesn’t have to be expensive or pretty to work!

The major parts of the POV display were things that [Sholto] had lying around. A couple of candy tins, a simple brushed hobby motor, an Arduino Pro Mini, 7 green LEDs, and an old hall effect sensor were all that were required. Fancy displays might use commercial slip rings to transfer power, but [Sholto] made it work on the cheap!

The two tins provide a base for the display and the negative supply for the Arduino. The tins are soldered together and insulated from the motor, which is hot glued into the lower tin. A paper clip contacts the inside of the lid, making the entire assembly a slip ring for the negative side of the Arduino’s power supply. Some copper braid rubbing on the motor’s metal case forms the positive side.

[Sholto] chose his resistors to slightly overdrive his green LEDs. This makes the display appear brighter in POV use. During normal operation, the LEDs won’t be driven long enough to cause damage. If the software locks up with LEDs on though, all bets are off!

[Sholto] includes software for a pretty darn cool looking “saw wave” demo, and a simple numeric display. With a bit more work this could make a pretty cool POV clock, at least for as long as the motor brushes hold up!

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