Building A Digital Compass With An Arduino

July 12, 2023 by 8 Comments

The magnetic compass has been a crucial navigational tool for around a thousand years or so, perhaps longer. While classical versions still work perfectly well, you can now get digital magnetometers that work in much the same way. [mircemk] decided to whip up a digital compass to demonstrate the value of these parts.

The build uses a HMC5883L magnetometer. While this can detect magnetic fields in three axes, just one is necessary for building a device that operates akin to a traditional compass. The output of the device is read by an Arduino Nano, which is hooked up to a string of WS2812B LEDs and a small OLED display. The LEDs display the bearing of magnetic north, while the OLED screen shows the current angle between the compass’s arrow and magnetic north.

It’s a tidy build that would be a great educational resource for teaching both electronics and navigational skills. We’ve seen similar projects before, like the hilarious Pizza Compass. Video after the break.

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Electronic Earrings Are PCB Art You Can Wear

June 24, 2023 by 4 Comments

If there’s one area of the human anatomy we rarely try to draw the eye, it’s the ears. Nonetheless, [DIY GUY Chris] has developed some LED earrings that should do exactly that.

The earrings are made using PCBs as the very body of the jewelry itself. The PCBs for each ear play host to eight WS2812 LEDs in a tiny 2020 form factor. The LEDs get their instructions from an ATtiny13-A AVR microcontroller, with some further supporting hardware to get everything playing happily together. Each earring runs off a single CR1220 coin cell, which sits on the obverse side of the earring to stay out of sight. The earrings are programmed with pogo pins to avoid the need for any bulky connectors.

By virtue of the tiny addressable LEDs, the earrings are capable of displaying full RGB colors. [DIY GUY Chris] has programmed the earrings with simple color fades, as well  as some fancier chase animations as well.

We’ve seen some great PCB jewelry before, too. Video after the break.

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Electronic Connect 4 Console Doesn’t Use LCD

May 28, 2023 by 9 Comments

You might think that making your own electronic games would require some kind of LCD, but lately, [Mirko Pavleski] has been making his using inexpensive 8X8 WS2812B LED panels. This lets even a modest microcontroller easily control a 64-pixel “screen.” In this case, [Mirko] uses an Arduino Nano, 3 switches, and a buzzer along with some 3D printed components to make a good-looking game. You can see it in action in the video below.

The WS2812B panels are easy to use since the devices have a simple protocol where you only talk to the first LED. You send pulses to determine each LED’s color. The first LED changes color and then starts repeating what you send to the next LED, which, of course, does the same thing. When you pause a bit, the array decides you are done, and the next train of pulses will start back at the first LED.

It looks like the project is based on a German project from [Bernd Albrecht], but our German isn’t up to snuff, and machine translation always leaves something to be desired. Another developer added a play against the computer mode. This is a simple program and would be easy to port to the microcontroller of your choice. [Mirko]’s execution of it looks like it could be a commercial product. If you made one as a gift, we bet no one would guess you built it yourself.

Of course, you could play a real robot. You could probably repurpose this hardware for many different games, too.

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Bringing The PIO To The FPGA

May 22, 2023 by 10 Comments

We’ve seen some pretty incredible hacks using the Raspberry Pi 2040. However, one of the most exciting bits of hardware onboard is the Programmable I/O (PIO). Not content with it just being a part of RP2040-based projects, [Lawrie Griffiths] has been porting the PIO to Verilog so anyone can enjoy it.

This particular implementation is based only on the spec that Raspberry Pi provides. For assembling PIO code, [Lawrie] uses Adafruit’s pioasm assembler they use for their MicroPython framework. There’s a simulator to test different programs, and the project targets the Blackice MX and the Ulx3s. A few example programs are included in the repo, such as outputting a pleasant guitar note over I2S and driving a chain of WS2812s.

The project is still incomplete but slowly making progress. It’s an incredible feat of reverse engineering. While the simulator can be used to debug programs, step through instructions, and inspect waveforms, the ultimate value of bringing the PIO to other systems is that now we can re-use the code. Things like the can2040, an implementation of the CAN bus protocol using the PIO. Or even a PIO-based USB host.

Visual Ear Demonstrates How The Cochlea Works

April 2, 2023 by 13 Comments

The cochlea is key to human hearing, and it plays an important role in our understanding of complex frequency content. The Visual Ear project aims to illustrate the cochlear mechanism as an educational tool.

The cochlea itself is the part of the ear that converts the pressure waves of sound into electrical signals for the brain. Different auditory frequencies excite different parts of the cochlea. The cells in the different parts of the cochlea then send signals to the brain corresponding to the sound it has picked up.

The Visual Ear demonstrates similar behavior on a strip of addressable LEDs. Lower LEDs coded in the red part of the color spectrum respond to low frequency audio. Higher LEDs step through yellow, green, and up to blue, and respond to the higher frequencies in turn. This is achieved at a high response rate with the use of a Teensy 4.0 running a Fast Fourier Transform on incoming audio, and then outputting signals to run a string of WS2812B LEDs. The result is a visual band display of 104 bands spanning 43 Hz up to 16,744 Hz, which covers most but not all of the human range of hearing.

It’s an impressive display, and one that makes a great music visualizer, too. When teaching the physics of human hearing and the cochlea, we can imagine such a tool would be quite useful.

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Building An Energy Sword Replica From Halo

April 1, 2023 by No comments

A good many of us whiled away the hours of our youths playing Swords Only deathmatch in Halo 2. The Energy Sword, aka the Plasma Sword, was the star of the show, with its devastating glowing blades granting us scoreboard domination. [Arnov Sharma] has now built a quality replica of this science-fiction weapon.

The build starts with a 3D design drawn up in Fusion 360. The parts are then 3D printed, with opaque filament used for the handle and translucent PLA filament for the “blade”. Inside the blade elements are twenty WS2812B LEDs, creating the characteristic glow that made the Energy Sword so tantalizing to find in game. An ATtiny85 is charged with running the LEDs, with the aid of an IP5306 chip to act as a boost converter for the lithium-ion battery supplying the juice.

[Anton] admits that the sword was built for the sole purpose of beautifying his maker space. That’s something we can respect, because we’d love to have one hanging on the wall at home. We’ve featured some other fun gaming replicas before, too.

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Compact Mouse Jiggler Keeps Boss Off Your Back

March 18, 2023 by 68 Comments

The work-from-home revolution enabled many workers to break free from the shackles of the office. Some employers didn’t like the loss of perceived control though, and saddled workers with all kinds of odious spyware to monitor their computer activity. Often, this involves monitoring mouse movement to determine if workers are slacking off or not. Mouse jigglers aim to fool these systems, and the MAUS from [MAKERSUN99] is one you can build yourself.

The MAUS is not a mechanical system that moves a real-life mouse on your desk. Instead, it directly injects emulated mouse movements via USB. It runs on an ATtiny85, which is able to spit out USB HID commands with the help of the V-USB software USB implementation. Along with the microcontroller, MAUS also features a red LED and a WS2812B RGB LED for user feedback. It’s also available on Tindie if your boss has you so busy that you don’t have time to build one.

Mouse jigglers came to prominence as working from home became mainstream. However, they’ve been around for years.

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