Push-Button Degaussing for an Arcade CRT

arcade degaussing control

[Ed] was tasked with adding push-button degaussing to an arcade cabinet’s CRT console. The display can be rotated to portrait mode for games that require it, but each time this is done, the magnetic fields get out of whack.

Fortunately, the schematics arrived with the display. [Ed] found that the degauss coil is connected in series with a PTC fuse in an odd arrangement that he didn’t agree with. He decided to use an SSR to switch the coil, and after making lots of transistor-based designs on paper, grabbed a nearby Arduino.

[Ed] took off the PTC and soldered in two wires to its pads for the SSR. He added a wire to the power supply decoupling cap to power the new deguassing circuit and connected the SSR to the Arduino as an open collector input. There was just enough space available to mount the relay to the frame’s base and the Arduino on the side. [Ed] wrote a short method to trigger the SSR and reconnected the PTC fuse. Now it degausses at power up as well as on demand.

The Fridge Hacking Guide by BrewPi

brewpi-fridge-conversion-51

The team behind BrewPi are at it again! This time they have created an online guide showing how to convert a min-fridge into a Raspberry Pi & Arduino controlled fermentation chamber. In it, they describe 3 possible options:

  • Option 1: Make a simple switched power cord, without hacking into the fridge electronics.
  • Option 2: Make a switched power cord, but also override or remove the thermostat.
  • Option 3: Rip out the thermostat and fully integrate the SSRs into your fridge (which is what [Koen] and [Elco] did).

First things first though. They had to clean the fridge. And depending on where they got it or how long it has been unplugged for, the inside might have been pretty rank and disgusting from mold growing out of every corner. This took a good hour or so to clean properly lest the brewing process get infected with external grossness. This is all worth it because a well-controlled fermentation chamber results in a superior batch of beer.

They put their laser cut case on top of the fridge, holding an LCD, Raspberry Pi, Arduino and the BrewPi Arduino shield. The Arduino reads the temperature sensors inside the fridge, the beer and the ambient temperature. Then it controls the SSRs they added to switch the compressor and a heater. Then, the cables were routed through the fridge and take control of the compressor.

[Read more...]

MIDI Melodies Make Moody Milieu

MIDI piano lights

In this beautiful, well-documented, cat-assisted hack, [capricorn1] adds visual dimension to his impressive piano skills by using his keyboard’s MIDI output to drive Edison bulbs.

He hung them from a rod of electrical conduit pipe and threaded the wires through it to a DB25 connector. The lights are controlled by an Arduino Mega plus a custom shield with an optocoupler to handle zero cross detection. He happened to already have a board with 12 SSRs on it from another project. All of the electronics are in a re-purposed switch box—the switches control four different modes: classic, velocity, scrolling, and automatic. You’ll see the scrolling mode in the video after the jump.

[capricorn1] used a small sampling of the Arduino MIDI Library, namely the note on/off functions and the control change function to handle his sustain pedal. He’s listed the full code for the project, which includes usage of the ipMIDI module for automation over WiFi.

If you don’t have a MIDI keyboard or any Edison bulbs, you could make a MIDI floor piano. You’re required to play both “Chopsticks” and “Heart and Soul” on it, though. Those are like the Hello, World for floor pianos.

[Read more...]

Arduino-Controlled Marquee Arrow Points the Way to Whatever You Like

Reader [pscmpf] really digs the scrolling light look of old marquee signs and as soon as he saw some Christmas lights with G40 bulbs, he was on his way to creating his own vintage-look marquee arrow.

We must agree that those bulbs really do look like old marquee lights or small vanity globes. [pscmpf] started by building, varnishing, and distressing the wooden box to display the lights and house the electronics. He controls the lights with an Arduino Pro and an SSR controller board. The 24 lights are divided into ten sections; each of these has its own solid-state relay circuit built around an MC3042 as the opto-coupler, with a power supply he made from a scrap transformer.

[pscmpf] shares some but not all of his code as it is pretty long. There are five patterns that each play at three different speeds in addition to a continuous ‘on’ state. In his demonstration video after the jump, he runs through all the patterns using a momentary switch. This hack proves that Arduino-controlled Christmas lights are awesome year-round.

[Read more...]

Update: Grow controller rebuilt to last

new-grow-controller

[The Cheap Vegetable Gardener] assembled his first grow controller about three and a half years ago. He’s been very happy with it and knows that he’ll be using it for years, maybe even decades to come. He just finished overhauling the grow controller design to help make sure he doesn’t burn down his garage one day. You have to admit, without knowing anything about the project this rendition does look safer than his original offering.

Pictured above is the weather-proof enclosure he used to house four mains-rated solid state relays. This box is isolated from the control hardware, providing heavy-duty utility plugs to interface with the heater, lights, fan, and water pump.  He mounted the Arduino board which controls the relays to the outside of the box, using the Ethernet wire to switch the SSRs. It uses a manufactured shield he designed which will help ease the pain of fixing the system if parts ever go bad.

Later on in the build he shows the grow light and heaters used in his operation. The heaters simply screw into light sockets; something we’ve never come across before.

RF switching module can learn new remotes

rf-remote-also-learns-by-itself

This breadboarded circuit is [Sergio's] solution to controlling appliances wirelessly. Specifically he wanted a way to turn his pool pump on and off from inside the house. Since he had most of the parts on hand he decided to build a solution himself. What he ended up with is an RF base station that can learn to take commands from different remote devices.

The main components include the solid state relay at the bottom of the image. This lets the ATtiny13 switch mains voltage appliances. The microcontroller (on the copper clad square at the center of the breadboard) interfaces with the green radio frequency board to its left. On the right is a single leaf switch. This acts as the input. A quick click will toggle the relay, but a three-second press puts the device in learning mode. [Sergio] can then press a button on an RF remote and the device will store the received code in EEPROM. As you can see in the clip after the break, he even included a way to forget a remote code.

[Read more...]

FireHero: Raspberry Pi Controlled Pyrotechnics

Fire Hero 3

To put on a live pyrotechnic show at a music festival, [Chris] built the FireHero 3. The result is remotely controlled flames shooting up to 100 feet in the air.

The system is controlled by a Raspberry Pi and an Arduino. A server runs on the Pi and allows a remote computer to control the system. The Pi sends commands over serial to the Arduino, which switches solid state relays that actuate the valves.

There’s also some built in safety features: the system won’t boot unless you have the right key and RFID tag, and there are pressure transducers and temperature sensors to ensure the system is operating safely. A CO2 actuated valve can quickly stop fuel flow in an emergency.

Vaporized propane creates the fireballs. The vapor is created by heating the supply tank in a hot water bath. An accumulation tank stores the vapor and custom built manifolds distribute it to the various flame cannons. At each cannon, a silicon nitride hot surface igniter (HSI) is used to ignite the flames once the valve is opened.

After the break, watch a video the the FireHero making some flames.

[Read more...]

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