A Laser Cut Word Clock

DIY laser cut word clock.

What is a word clock? A word clock is a clock that displays the time typographically that is also an interactive piece of art. Rather than buy one for $1500, [Buckeyeguy89] decided to build one as a present for his older brother. A very nice present indeed!

There are many different things that come into play when designing a word clock. The front panel is made from a laser cut piece of birch using the service from Ponoko. Additionally, white translucent pieces of acrylic were needed to keep each word’s light from bleeding into the neighboring letters. The hardware uses two Arduinos to control the LEDs and a DS3231 RTC for keeping accurate time. The results are very impressive, but it would sure make assembly easier if a custom PCB was used in the final version. For a one-off project, this makes a great birthday present.

The craftsmanship of this word clock is great, making it well suited for any home. What projects have you built that involve more than just electronics? Sometimes, quality aesthetics make all the difference.

Quick and Dirty RFID Door Locks Clean up Nice

homemade RFID Door Locks

[Shawn] recently overhauled his access control by fitting the doors with some RFID readers. Though the building already had electronic switches in place, unlocking the doors required mashing an aging keypad or pestering someone in an adjacent office to press a button to unlock them for you. [Shawn] tapped into that system by running some wires up into the attic and connecting them to one of two control boxes, each with an ATMega328 inside. Everything functions as you would expect: presenting the right RFID card to the wall-mounted reader sends a signal to the microcontroller, which clicks an accompanying relay that drives the locks.

You may recall [Shawn's] RFID phone tag hack from last month; the addition of the readers is the second act of the project. If you’re looking to recreate this build, you shouldn’t have any trouble sourcing the same Parallax readers or building out your own Arduino on a stick, either. Check out a quick walkthrough video after the jump.

[Read more...]

Solar Powered DIY Plant Watering System

Solar Powered Watering System

It’s great having fresh vegetables just a few steps away from the kitchen, but it takes work to keep those plants healthy. [Pierre] found this out the hard way after returning from vacation to find his tomato plant withering away. He decided to put an end to this problem by building his own solar-powered plant watering system (page in French, Google translation).

An Arduino serves as the brain of the system. It’s programmed to check a photo resistor every ten minutes. At 8:30PM, the Arduino will decide how much to water the plants based on the amount of sunlight it detected throughout the day. This allows the system to water the plants just the right amount. The watering is performed by triggering a 5V relay, which switches on a swimming pool pump.

[Pierre] obviously wanted a “green” green house, so he is powering the system using sunlight. A 55 watt solar panel recharges a 12V lead acid battery. The power from the battery is stepped down to the appropriate 5V required for the Arduino. Now [Pierre] can power his watering system from the very same energy source that his plants use to grow.

Non-Lethal Electric Chair Brings the Death Row Experience Home

Non-Lethal electric chair for Oculus Rift Hackathon

One of our trusty tipsters named [Arman] wrote in to tell us about this awesome little Horror VR Hackathon that sought to create a non-lethal electric chair, for a seriously creepy and shocking experience.

[Arman] works in a small prototyping shop, so when a few guys from the local VR group called to ask for help building a non-lethal electric chair, he thought they were joking — until they showed up at the shop! Finally understanding what they really wanted to do, he hooked them up with an EL wire power supply (high voltage AC, low amperage) for their first prototype.

Unfortunately the EL power supply driver took too much juice, so they called [Arman] back the next day to hack together some of those joke gum shockers instead — he hooked them up to an Arduino and they work like a charm.  [Read more...]

In-N-Out Boards Sans Hamburgers

board Before this project, [David]‘s office had a fairly terrible system to tell everyone who was in the office, who was out, and who wasn’t coming in today. Velcro and whiteboards will do the job, but arcade buttons and LEDs called to [David], leading him to create this In/Out Status Board.

The old system consisted of a whiteboard on the side of each partition, with velcroed labels indicating if a particular person was in the office today, out, sick, or on holiday. Inconvenient to change, and there was no single place everyone could look to see if a particular person was in or not. The new system consists of a four-person pod with four arcade buttons and WS2811 LEDs, an Arduino Nano, and a 433 MHz radio. The main panel is just a bigger version of the four-person pod, keeping track of everyone in the office.

A single button switch will change a person from being in to being out, with longer presses necessary for ‘sick’ and ‘vacation’. It’s interesting to note what’s not included in this build: A fingerprint scanner was out of the question, because that would effectively eliminate anyone ever being marked as ‘sick’. An RFID tag reader was out for the same reason. Also not included is a display. That’s just fine, really – [David] won’t be changing the labels very often, anyway, and that would just add to the cost and complexity of the project.

Door Lock Provides Peace of Mind With Real-Time Security

arduino door lock

[HSP] got tired of locking his door with a key, so he decided to upgrade to a keypad system which he’s designed himself.

It uses an Arduino Mega with the standard 44780 display, a standard keypad, and the “key override” (shown above) for fun. The locking mechanism is a standard 12V actuator based lock which was modified to run off of only 7.5V, by softening up the spring inside and running it upside down (as to let gravity help do the work). The whole system draws less than half a watt on standby, and engaging the lock peaks at only 4-7W.

What’s really clever about this design is how he locks it from inside the room. He’s programmed the Arduino to write 1 to address 128 of the EEPROM — at power on it will increment this by 1, and after 5 seconds, it will reset to 1. This means it can detect a quick power cycle, so you can lock the door by turning it off, turning it on for a few seconds, and turning it off and on again — he did this so he didn’t have to make a button or console, or any kind of wireless control on the inside. [Read more...]

Lego Drawing Machine Draws Block Shapes Best

Lego-drawing machine

Loving to draw but deathly afraid of pen ink, [Marcel] came up with a little drawing machine made out of Lego that will do it for him. It’s not a very complicated build but it does have several different components arranged such to complete a task, and that in itself is cool. Oh yeah, just kidding about the “afraid of pen ink” thing.

RC Car Servos are used to drive the pen in the X and Y directions. These servos only have a 180 degree range of motion which is not enough to move the pen very far. To increase the pen’s travel distance, [Marcel] attached a large gear to the servo which rotates a much smaller gear that rides on a rack gear attached to the bed. A Lego hinge takes the place of a Z axis and is used to set the height of the pen that is strapped to the machine via rubber band.

In order to make the machine draw, the user moves an analog joystick. The changing resistance values of the joystick’s potentiometers are measured by an Arduino. The Arduino then moves each servo to the appropriate position using PWM. If you’d like to know how to do this, check out the Knob Tutorial.

If you’re not ready to l’eggo your Lego drawing machines, check out this super complicated creation or this arm emulator that draws the Mona Lisa.

 

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