Arduino And IR Remote Turn Off Raspberry Pi

With all of the cool features on the Raspberry Pi, it is somewhat notable that it lacks a power button. In a simple setup, the only way to cut power to the tiny computer is to physically remove the power cord. [Dalton63841] found that this was below his wife’s tolerance level for electronics, and built a simple remote control for his Raspberry Pi.

[Dalton63841] started this project by trying to use the UART TX pin, but this turned out to be a dead-end. He decided instead to use an Arduino to monitor the 3.3V power rail on the Pi. When the Pi is shut down in software, the Arduino can sense that the Pi isn’t on any more and disconnect the power. The remote control is used to turn the Pi on. The Arduino reads the IR code from a remote and simply powers up the Pi. This is a very simple and elegant solution that requires absolutely no software to be installed on the Raspberry Pi.

We know that this isn’t the most technically complex project we’ve ever featured, but it is a good beginner project for anyone just getting started with a Pi, Arduino, or using IR. Plus, this could be the perfect thing to pair up with a battery-backup Raspberry Pi shutdown device that allows it to power itself down in a controlled way when a power outage is sensed.

A Simple Circuit For Testing Infrared Remote Controls

Every now and then a remote control acts up. Maybe you are trying to change the channel on your television and it’s just not working. A quick way to determine if the remote control is still working is by using a cell phone camera to try to see if the IR LED is still lighting up. That can work sometimes but not always. [Rui] had this problem and he decided to build his own circuit to make it easier to tell if a remote control was having problems.

The circuit uses a Vishay V34836 infrared receiver to pick up the invisible signals that are sent from a remote control. A Microchip 12F683 processes the data and has two main output modes. If the remote control is receiving data continuously, then a green LED lights up to indicate that the remote is functioning properly. If some data is received but not in a continuous stream, then a yellow LED lights up instead. This indicates that the batteries on the remote need to be replaced.

The circuit also includes a red LED as a power indicator as well as RS232 output of the actual received data. The PCB was cut using a milling machine. It’s glued to the top of a dual AAA battery holder, which provides plenty of current to run the circuit.

Hacking A Wireless AC Power Outlet

It’s always nice to see hackers pick up stuff headed for the landfill and put it back in action with a quick repair and upgrade. [Septillion] found a wireless remote controlled AC outlet in the junk bin and decided to do just that. A nice spin-off of such hacks is that we end up learning a lot about how things work.

His initial tests showed that the AC outlet and its remote could be revived, so he set about exploring its guts. These remote AC outlets consist of an encoder chip on the remote and a corresponding decoder chip on the outlet, working at 433MHz.  Since the various brands in use have a slightly different logic, it needed some rework to make them compatible. The transmit remote was a quick fix – changing the DIP switch selected address bits from being pulled low to high and swapping the On and Off buttons to make it compatible with the other outlets.

Working on the AC outlet requires far more care and safety. The 230V AC is dropped down using a series capacitor, so the circuit is “hot” to touch. Working on it when it is powered up requires extreme caution. A quick fix would have been to make the changes to the address bits and the On/Off buttons to reflect the changes already made in the remote transmitter. Instead, he breadboarded a small circuit around the PIC12F629 microcontroller to take care of the data and address control. Besides, he wanted to be able to manually switch the AC outlet. The relay control from the decoder was routed via the microcontroller. This allowed either the decoder or the local manual switch from controlling the relay. Adding the PIC also allowed him to program in a few additional modes of operation, including one which doubled the number of outlets he could switch with one remote.

LED Sign Brightens Up The Beach After Dark

[Warrior_Rocker’s] family bought a fancy new sign for their beach house. The sign has the word “BEACH” spelled vertically. It originally came with blue LEDs to light up each letter. The problem was that the LEDs had a narrow beam that would blind people on the other side of the room. Also, there was no way to change the color of the LEDs, which would increase the fun factor. That’s why [Warrior] decided to upgrade the sign with multi-colored LEDs.

After removing the cardboard backing of the sign, [Warrior] removed the original LEDs by gently tapping on a stick with a hammer. He decided to use WS2811 LED pixels to replace the original LEDs. These pixel modules support multiple colors and are individually addressable. This would allow for a wide variety of colors and animations. The pixels came covered in a weatherproof resin material. [Warrior] baked the resin with a heat gun until it became brittle. He was then able to remove it entirely using some pliers and a utility knife. Finally, the pixels were held in place with some hot glue.

Rather then build a remote control from scratch, [Warrior] found a compatible RF remote under ten dollars. The LED controller was removed from its housing and soldered to the string of LEDs. It was then hot glued to a piece of cardboard and placed into the sign’s original battery compartment. Check out the video below for a demonstration. Continue reading “LED Sign Brightens Up The Beach After Dark”

Covert Remote Protest Transmitters

As a piece of protest art, “Covert Remote Protest Transmitters” ticks all the boxes. An outdoor covert projector that displayed anti-globalization messages at a G20 summit is protest. To disguise it inside a surveillance camera body housing — sticking it to the man from inside one of his own tools — is art. And a nice hack.

However you feel about the politics of globalization (and frankly, we’re stoked to be able to get cheap tech from anywhere in the world) the open-source DIY guidebook to building the rig (PDF) makes up for it all.

They installed the camera/projector long before the summit, where it sat dormant on a wall. A cell phone inside turned on the projector’s light with each ring because they attached a relay to the cell phone’s speaker circuit. In the instructions there’s an example of using a light-dependent resistor (CdS cell) to do the same thing, relying on the phone’s backlight functionality instead. There are a lot of ways to go here.

The optics consist of a couple of lenses aligned by trial and error, then fixed in place to a balsa wood frame with hot glue. A big fat Cree LED and driver provide the photons.

The video documentation of the piece is great. It’s mostly the news media reacting to the art piece as a “security breach”. A security breach would be a gun or a bomb. This was an overhead projector displaying messages that were out of the organizers’ control. Equating security with the supression of dissent is double-plus-ungood. Touché, CRPT.

Anyway, while you’re getting prepped for your next protest, have a look at the Image Fulgurator.

SNES Controller Modified to be Completely Wireless

[Pat] was looking for a way to wirelessly control his Fire TV unit. He could have just went with one of many possible consumer products, but he decided to take it a step further. He modified a unit to fit inside of an original SNES controller. All of the buttons are functional, and the controller even features a wireless charger.

[Pat] started out with a Bluetooth video game controller marketed more playing video games on tablets. The original controller looked sort of like an XBox controller in shape. [Pat] tore this controller open and managed to stuff the guts into an original SNES controller. He didn’t even have to remove the original SNES PCB. [Pat] mentions that it was rather tedious to rewire all of the buttons from the original controller, but in the end it wasn’t too difficult. The only externally visible modification to the original controller is a small hole that was made for a power button.

In order to make this unit completely wireless, [Pat] also installed a Qi wireless charging module. Now, placing the controller on a charging pad will charge up the small LiPo battery in just about 45 minutes. This controller would be the perfect addition to a RetroPi or other similar project. If you’re not into Bluetooth, you can try using a Logitech receiver instead. Continue reading “SNES Controller Modified to be Completely Wireless”

Ultimate Remote is Ultimate

[Joedefa] had a Griffin Beacon Universal Remote that was collecting dust, and decided that it needed to stop collecting dust. He had a growing number of wireless devices in his house and found himself in need of a remote to control them all. The Griffin Beacon fit the bill, but most of his lights and outlets were RF controlled. So he did what hackers do best… broke out the screw driver and soldering iron and rewired it!

[Joedefa] is using an Attiny85 as the brains between an infrared LED and a RF transmit module (if anyone can identify the source of this module, please let everyone know in the comments).  A pair of red and green LEDs lets him know if the remote has received commands successfully.

It’s always nice to see a discontinued product made useful once more with a little ingenuity and an Arduino some hacking skill. Hat’s off to [Joedefa] for a righteous hack!