Don’t worry, the rhythms themselves aren’t random! That would hardly make for a useful drum machine. [kbob]’s creation does have the ability to randomly generate functional rhythms, though, and it’s all done on a breadboard.
The core of this tiny drum machine is two Teensy dev boards. One is an FM synth tuned to sound like drums, and the other is a random rhythm generator with several controls. The algorithms are from Mutable Instruments’ open source Eurorack modules. The entire thing fits on a breadboard with JIGMOD modules for the user interface. The machine runs on lithium batteries in the form of USB cell phone chargers. The battery holders were designed in Fusion 360 and 3D printed.
The function of the drum machine is pretty interesting as well. There are a set of triggers tied to the buttons on the machine. When a button is pressed, the drum machine plays that sound at the appropriate time, ensuring there are no offbeat beats. The potentiometers are polled once every millisecond and the program updates the output as required. There’s also a “grid” of rhythms that are controlled with two other knobs (one to map the X coordinate and the other for the Y) and a “chaos” button which adds an element of randomness to this mapping.
The modular nature of this project would make this a great instrument to add to one’s musical repertoire.It’s easily customizable, and could fit in with any of a number of other synthesizer instruments.
Continue reading “Modular Drum Machine Creates Random Rhythms”
Anyone into audio recording knows that recording drums is a serious pain. Mic setup and positioning can make or break a recording session. One particular hurdle is getting a great sound out of the bass drum. To overcome this, [Mike] has built a microphone using an 8″ woofer in an attempt to capture the low-end frequencies of his bass drum. Using a speaker as a microphone isn’t a new idea and these large diaphragm bass drum mics have taken commercial form as the DW Moon Mic and the now-discontinued Yamaha SubKick.
The project is actually quite simple. The speaker’s positive terminal is connected to Pin 2 of a 3-pin XLR microphone connector. The speaker’s negative terminal is connected to the connector’s Pin 1. [Mike] made a bracket to connect the woofer to a mic stand, which in turn was cut down to position the woofer at bass drum height. The setup is then plugged into a mixer or pre-amp just like any other regular microphone.
[Mike] has since made some changes to his mic configuration. It was putting out way too hot of a signal to the preamp so he added an attenuation circuit between the speaker and XLR connector. Next, he came across an old 10″ tom shell and decided to transplant his speaker-microphone from the open-air metal rack to the aesthetically pleasing drum shell. Check out [Mike’s] project page for some before and after audio samples.
A [Hank Drum], as explained here, is a steel drum-type instrument made out of a propane tank. The name comes from the [Hang] or [Hang Drum] which is significantly more expensive than that $40 or so an empty propane tank costs. Of course, you’ll have to do some work to get it to play beautiful music, which can be seen in a time-lapse construction video after the break.
The details of how this instrument was made can be found here, including how to lay everything out and cut out eight relatively neat “tongues” for producing different tones. I used a Dremel tool, but this can also be done using saber saw for a curved top. This method is explained here with a template, but the results may not be as neat.
If you want to try this yourself, make sure to use an empty, unused propane tank. This is extremely important. For another entirely different homemade instrument, why not check out the [Whamola] that we made a year or so ago? Continue reading “Making a Propane Tank Hank Drum”
If you’re looking to learn the art of playing Japanese drums, or Taiko, this hack, done as a school project by [Cornell] students, could be a really helpful aid. The project write-up is very impressive and includes a detailed explanation of their work, the source code, and a bill of materials if you’d like to try to duplicate this device.
The tutor device is able to tell between soft hits, hard hits, and rimshots using a piezoelectric sensor hooked up to an ATmega1284P microcontroller. This data can then be transmitted to the “follower” drum using an infrared transmitter. These beats can be used in several modes including: follow the leader, metronome, repeat after me, and drum battle mode.
Ok, maybe there’s no drum battle mode, but be sure to check out the demonstration of the Taiko teaching aid after the break. There’s a lot of details about the build, but they start some calibration drumming around 4:00 if you’d just like to see it in action. Continue reading “Japanese Drumming Sensei”
We think this is an intriguing take on half-tone art. It’s a CNC machine that uses an Arduino and two stepper motors to draw on a paper-covered drum. But you’re not just going to set it and forget it. To simplify the device, the Z-axis is not mechanized, but requires the dexterous opposing digit of a person to actuate.
The first prototype used a frame cut from plywood, but the developers moved to some attractive laser-cut Lexan for the final version. The rotating drum was inspired by observing the off-set printing process. It greatly simplifies the build when compared to a flat CNC bed. But including a Z-axis solution that could account for differently sized dots really opens a can of worms. Because of this, the choice was made not to automate that task, but to leave it up to the user. A clickable Sharpie does the marking. When the pen is in place, you click the plunger to hold the felt tip against the paper until a dot of the appropriate size has leeched onto the paper.
It’s not a bad solution to the problem. Especially if you don’t have the high-end milling equipment necessary to do this on a piece of plywood.
Sometimes projects are vast, complicated, and complex. Other times projects are a bit more on the simple. Today we thought we would share a couple projects with something in common that may be familiar sounding to the more experienced crowd, but may inspire a few readers new to the world of microcontrollers.
Continue reading “Today’s Arduino Minute”
[Wilfred’s] brother outfitted a snare drum with LEDs for Dutch Carnival. They faded through different colors randomly and were a nice addition to the normal looking instrument, but [Wilfred] suggested that the LEDs change color with each drum stroke. He set out to design a controller circuit to provide the functionality and ended with a small package based around an ATtiny2313 microcontroller. A piezo buzzer is used to detect the vibrations inside the drum, each hit triggering a different color combination. The LEDs fade to off after each impact as if dying along with the sound, and when not struck for 30 seconds the system defaults to a red heartbeat pattern. See for yourself after the break.
We’d love to see this feature added to each drum in one of those robotic drumsets. Continue reading “Disco drumming with piezo sensitive lighting”