Hackaday Links: February 9th, 2013

February 9, 2013 by Mike Szczys 6 Comments

Hobby electronics from 1982

[Lennart] came across one of his projects from several decades ago. It’s a twinkling star which blinks LEDs at different rates using some 7400 logic chips and RC timers.

Solder fume extractor

We’re still blowing the solder fumes away from us using our mouth, but this might inspire us to do otherwise. It’s a large PC fan mounted on a lamp goose neck. It clamps to the bench and is quite easy to position.

Ultrasonic liquid level measurement

Wanting a way to measure the liquid in these tanks without submerging a sensor, [JO3RI] turned to an Arduino and an ultrasonic rangefinder. His method even allows the level to be graphed as shown in his Instructible about the project.

Adding an ‘On’ light to save batteries

Dumpster diving yielded this electronic drum machine for [MS3FGX’s] daughter to play with. The problem is that pushing any of the buttons turns it on, it doesn’t have an auto-off, and there’s no way to know when it’s on. This is unacceptable since it runs on 5 AA batteries. His quick fix adds this green On LED. We wonder if he’ll improve upon this and add an auto-off feature?

CMOS Binary Clock

This is a portion of the guts of [Dennis’] CMOS Binary Clock project from the early 2000’s. He even built a nice case with a window for the LEDs which you can see are mounted perpendicular to the protoboard.

Arduino As An Inexpensive Ham Radio Frequency Counter

February 9, 2013 by Mike Szczys 8 Comments

[Todd Harrison] really has our number. Like him, we don’t want to spend money when we don’t have to, and hacking our own solutions is a lot more fun anyway. This time around he’s helping out a friend who is a ham radio enthusiast. The friend’s radio didn’t come with a frequency display, and buying the add-on would cost more than the radio did. So [Todd] has set out to build an Arduino frequency counter for a Kenwood TS-520S HF ham radio.

This post (and the video found after the break) doesn’t cover the entire project. It’s rather involved just to make sure that [Todd’s] initial idea is viable so he spends about 35 minutes explaining the problem, then measuring the radio outputs and testing to see that the Arduino can read them accurately. Because the radio has a very large range of operation, [Todd] will need to add external component to facilitate this. That extra circuit design will be the topic of the next project segment.

Continue reading “Arduino As An Inexpensive Ham Radio Frequency Counter” →

NASA Inspired Circadian Rhythm Lights

February 8, 2013 by Mike Szczys 10 Comments

circadian-rhythm-light-rig

After reading about an initiative between NASA and Boeing to develop lights for the International Space Station [Rasathus] decided to give it a go at building his own. The project uses RGB pixels to build a circadian rhythm light installation. Without the normal rise and fall of the sun the sleep wake schedule for the astronauts can be pretty rough. This uses color and intensity of light in a well-defined schedule to help alleviate that. [Rasathus] is trying to bring his project in well under the $11.1 million mark which was established for the ISS.

The light modules he’s using are from a strand of LEDs from Adafruit. Each is driven by a WS2801 controller, a common driver used for easy and complicated projects like this huge ball of light which our own [Jesse Congdon] tackled. The board above is the start of an adapter board for interfacing with the Raspberry Pi GPIO header. [Rasathus] wanted to make certain he didn’t fry the control electronics so he built some protection into this adapter. The control software is covered in the second portion of the write up. We’ve embedded the video from that post after the break.

Continue reading “NASA Inspired Circadian Rhythm Lights” →

Another Take On The 6502 Computer

February 8, 2013 by Mike Szczys 17 Comments

another-take-on-the-6502-computer

[Mark] is just starting off on his own 6502 computer odyssey. He was inspired by some of the other projects we’ve seen around here, like [Quinn Dunki’s] Veronica Project, but with a spin that leverages modern processors to alleviate some of the messy work. As you can see above, there’s an Atmel chip perched above the 65C02 processor. This chip not only feeds the processor data (through all those slightly diagonal yellow wires) but also provides the clock signal and operates the reset and bus enable lines.

This is more of a hello world post for [Mark]. The chip is simply running NOP commands right now. But it shows that the basic idea works, and the video after the break lets us see another time-saving aspect of the circuit. He’s using a character LCD to display memory location and data values. The plan is to get a blog going, which he’s hesitant to do as it takes valuable hacking time away from the project. We disagree. The write-up (although incredibly fun for us to read) ends up being a reference manual for him once the project starts to get really hairy.

Continue reading “Another Take On The 6502 Computer” →

SCARA Arm 3D Printer

February 8, 2013 by Mike Szczys 29 Comments

scara-3d-printer

[Quentin Harley] must really have wanted to test his snuff when it comes to mechanical engineering. He’s been hard at work for a couple of years now designing his own SCARA arm 3D printer. That link leads to a recent summary article in which he shows off the build as seen above. It’s not fully functional yet, but he’s at the point where it’s time to develop the driver circuitry and firmware so he’s close. His blog is dedicated to this single project so click around and see what he went through along the journey.

The SCARA arm is seen in blue, using a couple of stepper motors to move the extruder mount along the x and y axes. The bed itself moves along the Z axis via two precision rods with a threaded rod in the center. As you can see, some of the parts are made of wood, and he used PVC for the cross supports between the upper and lower base platforms. But the majority of the build uses 3D printed parts, including the arms, drive gears, and mounting brackets.

[Thanks Peter]

A Pair Of Automatic Fish Feeders

February 8, 2013 by Mike Szczys 3 Comments

a-pair-of-automatic-fish-feeders

Sometime the hacking topics come in waves. For instance, we were tipped off about this pair of automatic fish feeders just an hour apart from each other. Maybe it’s that time of year when people are about to go on Holiday and want to make sure their marine pets don’t go hungry?

The feeder on the left is a true hack. It’s built from a pair of servos and a pill bottle. An ATtiny85 drives the motors. One is mounted to the other, allowing the cap which catches and distributes the food to move along two axes. When it rotates into place under the pill bottle it bumps against a stick to open a flapper releasing more food.

On the right is a feeder that precisely doses the food. That’s because it includes a separate chamber for each feed. A worm gear drives the hopper, with screw heads pressing against a leaf switch for position feedback. This one is well designed and built to last.

Programming A 555 Chip

February 8, 2013 by Brian Benchoff 23 Comments

555

[Phillip] needed a way to trigger an input every 8 hours or so. This is a snap with a microcontroller with a proper timer, but he recently heard about a very cool programmable timer chip that’s also a 555. Of course CSS555 timer chip has an obscure programming interface, but that isn’t a problem when you can program it yourself with a parallel port.

The CSS555 timer chip (PDF…) is a strange little beast. It’s pin compatible with everyone’s favorite timer IC, but also has a programming mode that allows the output to trigger on every 1 cycle, every 10 cycles, and so on up to one output every million cycles. Basically, it’s a 555 with a huge programmable capacitor that only costs two bucks.

After building a programming circuit from a 74125 hex buffer chip, [Philip] connected his programmer to the parallel port of an ancient PC. For a little retrocomputing cred, he wrote a small app in Forth that pushes commands from the parallel port to the CSS555 chip, greatly increasing the time delay of the chip’s stock configuration.

It’s a neat build, and an awesome introduction to a really cool timer chip. Of course this could be easily replicated with a $2 microcontroller, but that wouldn’t give [Philip] the satisfaction of using a 555.