[Gr4yhound] has been rocking out on his recently completed synth guitar. The guitar was built mostly from scratch using an Arduino, some harvested drum pads, and some ribbon potentiometers. The video below shows that not only does it sound good, but [Gr4yhound] obviously knows how to play it.
The physical portion of the build consists of two main components. The body of the guitar is made from a chunk of pine that was routed out by [Gr4yhound’s] own home-made CNC. Three circles were routed out to make room for the harvested Yamaha drum pads, some wiring, and a joystick shield. The other main component is the guitar neck. This was actually a Squire Affinity Strat neck with the frets removed.
For the electronics, [Gr4yhound] has released a series of schematics on Imgur. Three SoftPot membrane potentiometers were added to the neck to simulate strings. This setup allows [Gr4yhound] to adjust the finger position after the note has already been started. This results in a sliding sound that you can’t easily emulate on a keyboard. The three drum pads act as touch sensors for each of the three strings. [Gr4yhound] is able to play each string simultaneously, forming harmonies.
The joystick shield allows [Gr4yhound] to add additional effects to the overall sound. In one of his demo videos you can see him using the joystick to add an effect. An Arduino Micro acts as the primary controller and transmits the musical notes as MIDI commands. [Gr4yhound] is using a commercial MIDI to USB converter in order to play the music on a computer. The converter also allows him to power the Arduino via USB, eliminating the need for batteries.
Continue reading “Arduino Synth Guitar Really Rocks”
LED’s are fun. They are easily seen, not to hard to hook up, and produce a nice glow that can be gazed at for hours. Kids love them, so when [Jens] daughter was born, he knew that he wanted to create a device that would alternate colors depending on the object’s movement.
He utilized a mpu6050 accelerometer to detect changes in position, and wired together an Arduino Nano, a 9V battery, and a 12 LED neopixel ring from adafruit. Design requirements were jotted down beforehand ensuring that any child playing with the Hypno-Jellyfish would not be injured in any way. For example, anything that fits in a child’s mouth, will go in that child’s mouth; meaning that any materials used must be non-toxic, big enough not to be swallowed, and drool proof/water proof. The kids will pull, and throw, and drop the toy as well, so everything has to be of sturdy quality too. Epilepsy is also a concern when dealing with LED’s. But, [Jens] project hit the mark, making something that is kid-friendly while at the same time enjoyable for anyone else who likes color-changing lights.
Continue reading “Hypno-Jellyfish is Great for Kids (and Kids at Heart)”
Here’s a hack centered around something a lot of people have sitting around: a PS/2 keyboard. [serdef] turned a Harry Potter-edition PS/2 into a combination synth keyboard and drum machine and has a nice write-up about it on Hackaday.io.
For communication, he tore up a PS/2 to USB cable to get a female mini DIN connector and wired it to the Nano. He’s using a Dreamblaster S1 synth module to generate sounds, and that sits on a synth shield along with the Nano. The synth can be powered from either the USB or a 9-volt.
Keymapping is done with the Teensy PS/2 keyboard library. [serdef] reused a bunch of code from his bicycle drummer project which also employed the Dreamblaster S1. [serdef] is continually adding features to this project, like a pot for resonance control which lets him shape the waveform like an analog synth. He has posted some handy PS/2 integration code, his synth code, and a KiCad schematic. Demo videos are waiting for you across the link. Continue reading “PS/2 Synth Will Knock You Off Your Broom”
Okay, so he doesn’t have Grandma riding in it that we know of, but [zim] recently decided to turn a Jazzy mobility chair into “a radio-controlled platform for mischief”. RC offers more range than wifi or bluetooth, and he was able to find a reasonably priced secondhand radio on Craigslist. However, he found out that in the event of signal loss, the receiver keeps sending the last commands to the speed controller. [zim] didn’t want his 150 lb (68kg) mischief platform getting loose, so he devised a fail-safe that cuts power to the motor when the signal is lost.
[zim] discovered that the receiver returns channel 3 (the throttle) to a preset condition whenever the signal is lost. He used a 24V HVAC relay controlled by an Arduino Nano to sample the PW on channel 3 and shut it off when either the throttle or the signal are cut.
If Grandma is feisty, you could build this caged-in version with a shopping cart.
Continue reading “How to Stop Grandma’s Wheelchair If She Goes Out of RC Range”
[Trandi] can check ‘build a self-balancing robot’ off of his to-do list. Over a couple of weekends, he built said robot, and, in his own words, managed not to over-design it. It even kept the attention of his 2-year-old son for several minutes, and that’s always a plus.
He was originally going to re-purpose one of his son’s RC cars, but didn’t want to risk breaking it. Instead, he designed a triangular 3-D printed chassis to hold a motor and some cogs to fit both the motor shaft and some re-used Meccano wheels. [Trandi]’s design employs an MPU 6050 6-DOF IMU for the balancing act and is built on an Arduino Nano clone.
[Trandi] is controlling the motor with an L293D, which has built-in flyback diodes to minimize spikes. He found that the Nano clone was not powerful enough to handle everything, so he added an L7805CV voltage regulator. After the break, watch [Trandi]’s cute bot tool around on various types of terrain, with and without a payload.
Don’t have an IMU lying around? You don’t really need one to build a self-balancing bot, as this IR-based lilliputian bot will demonstrate.
Continue reading “Self-Balancing Robots Wobble, But They Don’t Fall Down”
Security researcher [Fran Brown] sent us this tip about his Tastic RFID Thief, which can stealthily snag the information off an RFID card at long range. If you’ve worked with passive RFID before, you know that most readers only work within inches of the card. In [Fran’s] DEFCON talk this summer he calls it the “ass-grabbing method” of trying to get a hidden antenna close enough to a target’s wallet.
His solution takes an off-the-shelf high-powered reader, (such as the HID MaxiProx 5375), and makes it amazingly portable by embedding 12 AA batteries and a custom PCB using an Arduino Nano to interpret the reader’s output. When the reader sees a nearby card, the information is parsed through the Nano and the data is both sent to an LCD screen and stored to a .txt file on a removable microSD card for later retrieval.
There are two short videos after the break: a demonstration of the Tastic RFID Thief and a quick look at its guts. If you’re considering reproducing this tool and you’re picking your jaw off the floor over the price of the reader, you can always try building your own…
Continue reading “RFID Reader Snoops Cards from 3 Feet Away”
The VertiBOT is a self balancing robot project taken on for the purpose of exploring how the sensors work in conjunction with some PID algorithms.
[Miguel] didn’t roll any extras into the build. But you have to admit that makes it look interesting. There’s almost nothing to it and yet, as you can see in the clip after the break, he accomplished everything he set out to.
The body and wheels are 3D printed, with black bands for tires to help give it some traction. Note the connection in the center of the body which allowed him to make a longer part by printing in two stages. On the electronic side of things he’s using an Arduino Nano. A level converter lets it communicate with the 6 DOF IMU board which is used to detect movement. Three potentiometers provide a way for him to tweak the PID loop without having to bother with reflashing any code. And of course there’s an option to control it remotely thanks to a Bluetooth module also in the mix.
Continue reading “Clean and minimal self-balancing robot”