Automated Aquarium Fertilizer Doser

aquarium-auto-doser

If you are using live plants in your aquarium you must remember to fertilize them at regular intervals. Being a bit forgetful, [Deven] automated the process by building this auto-doser.

There are three different chemicals which are dispensed by the system. They are stored in the drink bottles seen above. Each has a plastic tube which runs up to the dosing motors mounted on the black box. [Deven] sourced the motors from eBay. They are designed for this type of application.

Inside the black box is the Arduino that handles timing and switches the motors. The control circuitry is protected using one MOSFET for each. To keep the fish safe the outflow is directed right into the aquarium pump so that the concentrated chemicals are quickly dispersed through the entire tank.

Now that he’s made it this far he might as well add the ability to feed the fish and control the lighting.

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Hackaday Retro Edition Roundup

Retro

The Hackaday retro edition hasn’t been updated in a while, and for that I am very sorry. Still, digging through my email reveals quite a lot of very cool retro computers that were able to load the retro edition over the Internet, and it would be a terrible shame to let these awesome submissions die in my inbox. Without further adieu, here are the best retro computers that have been sent in over the last few months:

[Scott] got his Mac SE to load up the retro edition. This was a chore; after getting a serial connection from his SE to the outside world, [Scott] realized he didn’t have a browser on his retro mac. 800k drives are a pain, it seems. He eventually got everything running in a terminal session, and the retro edition loaded beautifully.

How about another Mac? This one is [Raymond]’s Mac II, the first not-all-in-one Macintosh. NuBus Ethernet card, Netscape 2.02, and 26 years of history behind this machine.

Here’s a weird one: it’s a Siemens interactive display originally used for a building management display. It has a 10 inch touch screen display at 640×480 resolution and runs Windows CE 5.0. After fiddling with some files, [Nick] managed to get the networking running on this machine and tried to load Google. Anyone who has played around with the class of machines we seen for retro submissions knows what happened next (nothing), but luckily [Nick] remembered Hackaday has a retro site. The rest is history.

[Kyle] has a really cool box on his hands. It’s a Compaq 486SX overclocked from 25MHz to 33MHz. 20 Megabytes of RAM, network card, and a Soundblaster 16 make this computer from 1993 a very respectable box for old DOS gaming. It can also browse the web with Arachne.

Finally, [cnlohr], the guy who made his own electron microscope  never mind, he’s still awesome and can manufacture glass PCBs at home, found an old green screen CRT while cleaning out a friend’s place. He hooked it up to one of his glass PCB AVR microcontroller things and did the usual text terminal fare; ASCII Star Wars with telnet and using lynx to load up the retro site. It’s only a 48-column display, but the retro edition is surprisingly readable. Very cool.

Raspi Internet Radio With Google Music

SAMSUNG

It’s not his first Internet radio, but [Matthias]’ modernization of a classic Bakelite radio is a real, functional piece of art. Not only does it retain the look of an old radio, it also has the capability to listen to streams and his entire MP3 collection through the Internet.

For the software, [Matthias] used jquery to pull down web radio streams and soon figured out how to play all his MP3s through Google Music. This, and a web-based remote for his mobile device, allows the new old-school Internet radio to play everything [Matthias] would ever want to listen to.

The controls for the radio are rotary encoders, with indication provided by a really fabulous numbered LED display (seen above) replacing the 70-year-old tuning dial. These numbers indicate both the current Google Music playlist or the currently playing Internet stream, depending on what mode the selector knob is at.

It’s a beautiful piece of work, and the knobs and dials look like something that could have come from a real 70-year-old radio. That’s a win in our book.

Nikkor Optical Glass

Glass work is always a feast for the eyes, especially when it is hot glass. Watch as a Nikkor lens is made from beginning to end. It is wonderful to see the care taken to search by eye for defects, refraction issues, clarity etc. It may just be for the video, but it seems that the workers truly do take pride in their product.

What I found somewhat surprising was the amount of work that went into refining the glass BEFORE it was even put into a lens mold. I would have assumed that much of the work would have come after.

Dead Simple Jamming Gripper Design

dead-simple-jamming-gripper

This jamming gripper design is the simplest we’ve seen so far. It uses a syringe to generate the suction necessary for the orange appendage to grip an object.

As with previous offerings this uses coffee grounds inside of a balloon. When pressed against an object the grounds flow around it. When a vacuum is applied to the balloon those grounds are locked in place, jamming themselves around the item for a firm grip. About a year ago we saw a hardware-store grade design which used a vacuum pump for suction and a shower head as the gripper body. This time around the plastic syringe serves as both.

The plastic tip was cut away and the resulting hole covered with a cloth to keep the coffee in place. After installing the coffee-filled balloon the grip can be operated by pulling the plunger to lock the grounds in place. It’s not going to be as easy to automate as a pump-based rig. But if you just want to toy with the concept this is the way to go.

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A Very Tiny Gamma Ray Detector

gamma

When you think of a radiation detector, you’re probably thinking of a Geiger tube and its high voltage circuitry. That isn’t the only way to measure gamma radiation, though, and [Alan] has a great circuit to measure even relatively weak radiation sources. It uses a very small photodiode, and draws so little power it’s perfect for projects with the smallest power budgets.

The detector circuit uses a miniature solar cell and a JFET wired up in a small brass tube to block most of the light and to offer some EM shielding. This, in turn, is attached to a small amplifier circuit with a LED, Piezo clicker, and in [Alan]’s case a small counter module. The photodiode is actually sensitive enough to detect the small amounts of gamma radiation produced from a smoke alarm americium source, and also registers [Alan]’s other more powerful radioactive sources.

The circuit only draws about 1mA, but [Alan] says he can probably get that down to a few micoAmps. A perfect radiation sensor for lightweight and low power applications, and gives us the inspiration to put a high altitude balloon project together.

Keurig Hack Now Automatically Fills The Water Reservoir

keurig-automatic-water-fill

This hack makes your Keurig experience fully automatic. For those that aren’t familiar with the hardware: this type of coffee maker includes a water reservoir. Coffee is brewed One cup at a time by drawing from that water, quickly heating it, then forcing it through disposable pods containing coffee grounds and a filter. This takes the user-friendly design one step further by automatically keeping the water full.

This goes beyond the last water reservoir hack we saw. That one routed a water line to the machine, but included a manually operated valve. [Eod_punk] added a solenoid valve and level sensor in this project. The level sensor is submerged in the tank and is monitored by a Basic Stamp microcontroller. When the level is low the BS1 drives the solenoid via a transistor, letting the water flow. This is all shown in the video below.

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