Blinking An LED Passively

It is a pretty common first project to use an Arduino (or similar) to blink an LED. Which, of course, brings taunts of: you could have used a 555! You can, of course, also use any sort of oscillator, but [Mustafa] has a different approach. Blinking an LED with three resistors and a capacitor. Ok, ok… one of the resistors is a light-dependent resistor, but still.

In reality, this is a classic relaxation oscillator. The capacitor charges until the LED lights. This, however, causes the capacitor to discharge, which eventually turns off the LED, and the process starts again.

There is one wrinkle that could be considered a feature. In daylight, the capacitor will stay in the off state, so the blinking only occurs in darkness. Of course, the resistor also has to have a sufficient view of the LED. You might use this as a safety light that only works in the dark.

A simple circuit, but it just goes to show that we tend to forget the simple solutions in a world where a computer costs less than a dollar.

Of course, you can get a chip whose sole purpose is to blink LEDs. We always like examples of doing more with less.

Continue reading “Blinking An LED Passively”

Blinky Project Is 6502s All The Way Down

Virtually any platform you might find yourself programming on has some simple method of running a delay. [Joey Shepard] got rather creative on a recent project, though, relying on a rather silly nesting method that we’re calling 6502s All The Way Down.

The project in question was a simple PCB that was shaped like a robot, with blinking LED eyes. Typically, you’d simply reach for the usual sleep() or delay() function to control the blink rate, but [Joey] went off-piste for this one. Instead, the PIC32 on the board runs a 6502 emulator written in MIPS assembly. This emulated 6502 is then charged with running a further 6502 emulator coded in 6502 assembly, and so on, until there’s 6502 emulators running six-deep on the humble microcontroller. The innermost emulator runs a simple program that blinks the LED eyes in a simple loop. With the overhead of running six emulators, though, the eyes only blink at a rate of roughly once every two seconds.

It’s an amusing and complicated way to write a blink program, and we applaud [Joey] for going to all that trouble. We imagine it was a great way to learn about programming the PIC32 as well as emulation in general. Meanwhile, if you’re working on your own emulator feats, be sure to let us know!

Coin Cell Hacks That Won The Coin Cell Challenge

It’s amazing what creative projects show up if you give one simple constraint. In this case, we asked what cool things can be done if powered by one coin cell battery and we had about one hundred answers come back. Today we’re happy to announce the winners of the Coin Cell Challenge.

Continue reading “Coin Cell Hacks That Won The Coin Cell Challenge”

Horten Fyr Is Norwegian For Blinkie

Our Norwegian is pretty weak, so we struggled a little bit with the documentation for a big public LED art project in the lighthouse (translated) in Horten, Norway. But we do speak the universal language of blinkies, and this project has got them: 3,008 WS2812b LEDs ring the windows at the top of the lighthouse and create reactive patterns depending on the wave height and proximity of the ferry that docks there.

This seems to be an evolving project, with more features being added slowly over time. We love the idea of searching for the WiFi access point on the ferry to tell when it’s coming in to port, and the wave height sensor should also prove interesting data, with trends at the low-frequency tidal rate as well as higher frequency single waves that come in every few seconds. What other inputs are available? How many are too many?

It’s so cool that a group of tech-minded art hackers could get access to a big building like this. Great job, [Jan] and [Rasmus] and [everyone else]!

Continue reading “Horten Fyr Is Norwegian For Blinkie”

Building A Blink Based Input Device

OLYMPUS DIGITAL CAMERA

Fans of the AMC show Breaking Bad will remember the Original Gangsta [Hector Salamanca]. When first introduced to the story he communicates by ringing a bell. But after being moved to a nursing home he communicates by spelling out messages with the assistance of a nurse who holds up a card with columns and rows of letters. This hack automates that task, trading the human assistant for a blink-based input system.

[Bob Stone] calls the project BlinkTalk. The user wears a Neurosky Mindwave Mobile headset. This measures brainwaves using EEG. He connects the headset to an mBed microcontroller using a BlueSMiRF Bluetooth board. The microcontroller processes the EEG data to establish when the user blinks their eyes.

The LCD screen first scrolls down each row of the displayed letters and numbers. When the appropriate row is highlighted a blink will start scrolling through the columns until a second blink selects the appropriate character. Once the message has been spelled out the “SAY!” menu item causes the Emic2 module to turn the text into speech.

If you think you could build something like this to help the disabled, you should check out thecontrollerproject.com where builders are connected with people in need.

Continue reading “Building A Blink Based Input Device”

Add Motorized Blinds To Your Home Theater

motorized-blinds

[Chipsy] found himself with an interesting problem. The room that serves his home theater has a wall mirror which reflects part of the screen during viewing. In an otherwise dark room this was very distracting. His solution was to add a blind that covers the mirror during viewing, but who wants to constantly pull that down and back up again? Since the motorized projection screen he is using has a remote control he figured out a way to motorize the blind and synchronize it with the screen’s remote.

The screen uses mechanical relays to switch the motor. He patched into these with an Arduino to detect whether the screen was going up or down. It was easy enough to use his own relay and motor with the blind, but he needed a way to stop the blind once it was in position. For covering up the mirror he simply sets an 18 second timer, but for retracting the blind he wanted precise alignment so he added a magnet and sense its position with a reed switch. See the synchronized screen and blind in the clip after the break.

Continue reading “Add Motorized Blinds To Your Home Theater”

Blinking Light Switch

In addition to being a great replacement for that aging eye patch, these specs act as a light switch. By watching your eyelids, they are able to kill the lights whenever you blink.

The installation is a shared experience piece conceived by [Michal Kohút]. He wanted to illustrate the constant blinking we all do but rarely think about. The system uses an Arduino to capture events from the blink sensors and switch the lights accordingly. This way the wearer doesn’t experience a loss of illumination, but the observer does. Check out the video after the break for a quick demonstration.

One of the commenters from the source article shared a video link to another blink-based light project. That one uses electrodes attached to skin around your eye in order to detect eyelid motion.

Continue reading “Blinking Light Switch”