Virtual LCD Using Python

July 11, 2015 by 6 Comments

[Prashant Mohta] got hold of a Raspberry Pi, a 16×2 LCD display and got down to writing a simple game in Python. Pretty soon, he realized that it was cumbersome to have the Ras-Pi and LCD connected when all he wanted to do was write the code. So he wrote a simple Python module which renders the LCD on his computer display. A simple, quick, useful hack.

[Prashant]’s code relies on the use of Pygame, a set of Python modules designed for writing games. His code uses just two functions – one to define the LCD (characters and number of lines) while the other draws the characters on the screen by looking up an array. The code is just under 20 lines and available from his Github repo. It will be useful to those who are getting started on Python to help them understand some basics. Python is awesome and writing Python code is pretty simple.

This might draw some flak from the naysayers so if you’re commenting below on the merits, or not, of Python, just keep your comments civil and healthy. In the video below, unrelated to this hack, [Raymond Hettinger] talks about “What makes Python so Awesome”!

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Non-Invasive Smart Electricity Meter

July 11, 2015 by 44 Comments

There are a lot of ways to measure energy usage in the home, but most of them involve handling mains voltage. Not only that, but sometimes they require handling mains voltage before it gets through a breaker panel or fuse box, meaning that if you make a mistake there are a lot of bad things that can happen. [Yonas] has been working on this problem, and has come up with a non-invasive, safer way to monitor electricity consumption without having to work directly on live wires.

Please note that you should still not be working on mains voltage without proper training, but if you have the required know-how then the installation should be pretty straightforward. The project is based on the Spark Core, and uses clamp-on current sensors to measure energy use. The sensors wrap around the mains cable, meaning you don’t have to disconnect anything to hook them up. The backend runs on a LAMP server which could be a Raspberry Pi if you have one. [Yonas] runs it on a hosted server as a matter of preference.

All of the source code for this is available, and assuming you can get your hands on the current sensors this could be a great way to get started monitoring your energy usage in the house. Be sure to check out the video below for a demonstration of the operation of this device. Of course, if you have a gas line you’ll need this energy monitoring setup too.

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Natural Materials For Nature’s Call

July 11, 2015 by 19 Comments

When it comes to picking out high-end fixtures and appointments for your bathroom remodel, there are tons of choices out there these days. Sure, that double-slipper tub or  $2500 stainless steel toilet can make a statement, and even the local Big Box Home Store has some pretty unique stuff. But for a one of a kind sink, follow [The Samurai Carpenter]’s lead and carve a sink out of a boulder.

Capture2Starting with a stone he found off the porch of his house, [Samurai Carpenter] was able to rough out the shape of the basin with a diamond-bladed cutoff saw. A few plunge cuts within a hand-sketched outline gave him the room needed to hog out most of the material with a cold chisel and hammer. A diamond wheel on an angle grinder, along with a chisel bit on an impact drill, got him down to the final smooth finish. After the break there’s a video showing the final installation, including drilling out the drain hole and mounting the sink to the vanity, which is a beautiful rough-cut slab of what appears to be locally sourced wood. The whole installation looks fantastic and appears to function well; our only quibble is there’s no overflow in the basin, but it’s hard to see how he could have provided one without significantly complicating the project and potentially ruining the aesthetic.

Although they may not fit in with the natural vibe of his remodel, either this or this tricked out mirror could complete a high-end  bathroom remodel.

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Hackaday Prize Entry: A Clock For Alternate Timebases

July 10, 2015 by 15 Comments

There is a strange clock in the waiting room of Lord Vetinari, Patrician of Ankh-Morpork. While this clock keeps accurate time overall, the ticks and tocks are out of sync, occasionally missing a tick altogether. The net effect is one of turning one’s brain into a sort of porridge.

Yes, a Vetinari Clock has made its way into The Hackaday Prize. This isn’t a clock that’s random yet accurate over long time spans; this is a complete replacement for run-of-the-mill clock movements you can find at any craft store.

In addition to the Vetinari Clock, [Nick Sayer]’s Crazy Clock can be programmed as a sidereal clock (3m 56s fast per day), a Martian clock (39m 36s slow per day), and a tidal clock (50m 28s slow per day), as well as some ‘novelty’ modes that still have 86400 ticks per day ranging from subtle to ‘clown car’ levels of craziness.

[Nick] is gunning for the ‘best product’ category for the Hackaday Prize, and for that he’s designing a board to be a direct replacement for the board in a Quartex Q80 clock movement. With this new board, [Nick] can replace the electronics in this movement in just a few minutes. Being built around an ATtiny45 means it’s infinitely hackable. A clock with this movement would be a great product, although judging from the video below, not one we would want to be around all day.

The 2015 Hackaday Prize is sponsored by:

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CD Execution Chamber Sends Old Discs Off With A Bang

July 10, 2015 by 22 Comments

Welded steel safety cage? Check! Polycarbonate blast shield? Check! Vacuum cleaner motor wired to an inviting red button? Double check! Stack of CDs to dispose of as destructively as possible? [Firas Sirriyeh] has got you covered with his CD Terminator 1.0.

While [Firas’s] build log is a little short on descriptive text, there’s really no need for it. His pictures tell the tale. The combination media shredder and interactive performance art piece is a stoutly constructed affair, which you’d want anything capable of flinging razor-sharp plastic and Mylar shrapnel to be. [Firas] has displayed his CD execution chamber at the Jerusalem Mini Maker Fair 2015 (in Hebrew; English link) and the Musara Mix Festival where the must-see video after the break was shot (mildly NSFW language). Some CDs give up the ghost very quickly, but one held out for a remarkable long time before finally exploding; you can see it flexing and warping in a way that almost appears to be slow-motion.

For those who’d rather not fuss with all that bothersome safety, there’s always this automatic CD launcher to play with.

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Dewalt Radio Repair

July 10, 2015 by 19 Comments

We’re suckers for repair videos and this Dewalt worksite radio repair (YouTube Link) from Hackaday alum [Todd Harrison] is no exception. Like a detective story, we’re always trying to guess who did it.

In his first video [Todd] traced the issue down to a faulty 6 volt regulator which was pushing out 8 volts. He fixed that by hacking a LM317 into the circuit to replace the original non-adjustable part. That helped but after a few days the radio failed again. So here he traced out the voltages to find the second culprit. Along the way, we get to see some of the nicer features of his Fluke 87 and 289 meters. As well as puzzling over the some of the design decisions in the radios construction, before identifying the final issue.

We won’t spoil the surprise, but find out how Todd solves this riddle, wrapped in a mystery, inside an enigma in the video below!

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Camera Light Meter

Upgrading An Old Camera With A New Light Meter

July 10, 2015 by 11 Comments

[Marc] has an old Voigtländer Vito CLR film camera. The camera originally came with an analog light meter built-in. The meter consisted of a type of solar panel hooked up to a coil and a needle. As more light reached the solar panel, the coil became energized more and more, which moved the needle farther and farther. It was a simple way of doing things, but it has a down side. The photo panels stop working over time. That’s why [Marc] decided to build a custom light meter using newer technology.

[Marc] had to work within the confines of the tiny space inside of the camera. He chose to use a LM3914 bar display driver IC as the primary component. This chip can sense an input voltage against a reference voltage and then display the result by illuminating a single LED from a row of ten LEDs.

[Marc] used a photo cell from an old calculator to detect the ambient light. This acts as a current source, but he needed a voltage source. He designed a transimpedence amplifier into his circuit to convert the current into a voltage. The circuit is powered with two 3V coil cell batteries, regulated to 5V. The 5V acts as his reference voltage for the display driver. With that in mind, [Marc] had to amplify this signal further.

It didn’t end there, though. [Marc] discovered that when sampling natural light, the system worked as intended. When he sampled light from incandescent light bulbs, he did not get the expected output. This turned out to be caused by the fact that incandescent lights flicker at a rate of 50/60 Hz. His sensor was picking this up and the sinusoidal output was causing problems in his circuit. He remedied this by adding two filtering capacitors.

The whole circuit fits on a tiny PCB that slides right into position where the original light meter used to be. It’s impressive how perfectly it fits considering everything that is happening in this circuit.

[Thanks Mojay]