Grove I2C Touch Sensor Midi keyboard
Create a Midi keyboard with 4 buttons with the Seedstudio Grove Kit touch sensor.
- It uses the USB MIDI Library with an Arduino Leonardo,
- the Arduino USB interface can be used directly as an MIDI Interface
Repository and Files: https://github.com/Sonicrobots/Capacitive-Touch-Midi-Keyboard/blob/master/main.ino
We wanted to create light effect: short fades of 10W Leds which can be put on stage and are triggered via MIDI.
- 8 Channels
- Up to 10W LEDs at 12V per channel
- One LED Driver CAT 4101 per channel
- PWM Dimming of the brightness via Midi
- MIDI-IN and through
We used a dedicated LED Driver for each channel. Its the CAT 4101 which can drive up to 1A. A TLC5940 creates the PWM Signal. Up to 16 PWM Channels from the TLC (here we use only 8) are controlled via SPI from an ATMEGA168. Like this the load of the ATMEGA is kept low when a lot of dimming is performed. Midi-In is straight forward through an Optocoppler.
The MIDI Channel can be set with an hex coded 16 stage switch.
Our sketch contains a programm for fast dimming of the LEDs. Like this an LED will flash and slowly decay, which is a cool effect together with sound. You can see an example here (with 3W LEDs):
You can of course write your own sketch using ours. A good start is the example in the TLC5940 Arduino Library.
You don’t own a haunted castle but still want that Scottish chic of a “ghost chateau”? Make your own ancestors portray with automatic moving eyes and easily scare away unwanted guests!
We all know that old movies, where the young couple is staying in the haunted castle for the first night and gets scared away by pictures of some beardy ancestors, where the eyes seem to follow the spectators. In the end its just the butler who is spying from behind to get the heritage … but anyway. So you want to build one of these pictures, too. It’s not hard!
Before you start
- Time: 6-8h building time + time for the stuff you order online to arrive (days!)
- Level: Mid. A little programming, soldering and general handcrafting skills required
- You need: standard Tools (cutter, drill, screw driver),
- Arduino Uno,
- Standard Servo Motors from Futuba or Hitec e.g. this
- Hot Glue,
- Frames with old pictures (see below),
First you need a picture of your loved (or hated) one. A good portray in a high resolution (> 2MB in size) is recommended. Some photoshop magic later you have the picture with a custom background you find in the Internet. Put it into an online oil painting generator to create an even more old school look.
Now you need one or two framed pictures from the flee market.
Cut away the original background – maybe you can reuse it if its hard wooden sheet. In other cases cut some fresh wooden sheet of 2-5mm thickness.
Measure the frame and rezise the digital portray accordingly. We printed the photos out on A1, 230g/cm linen structure paper as a digital print (in europe yuo can use flyeralarm).
When the prints come from the printing service you can start making! We reused the background from the original frame picture we got from the flee market, but you can use any type of (wodden) material thats fits in the frame. We recommend a thickness of 2-6mm.
Now its time to cut the shape of the print as well as the eyeballs of your loved or hated on. A wonderful job, plus you have spare eyeballs now!
Now mark on the wooden background where the eyes are sitting. Now you need eyes. Its not so easy to get decent eyeballs in the Internet (we haven’t checked the dark web though), so you are very lucky, because we prepared some for you! You can find a print ready A4-pdf with fitting eyeballs here. Adjust the size when you have a bigger / smaller image and print them out on A4.
Take your background wood and mark where eyes will go. Measure it with the eyeballs you arleady have. Cut out a square as in the picture below.
Glue the eyes to the remaining wood you just cut out (which you made a little smaller on both small sides so it can move!)
We had a 3D-printer so we could print a holder. You can find the STL files in the github repo below. If you don’t have acess to a printer or use another type, we recommend building something similar from wood. The following steps are how we did it with our setup. It will probably differ if you want to rebuild this. Use your imagination and handcrafting skills to replicated the functions.
On the eyes-sqaure we used an holder (the black one) and a terminal thread to hold the acrylic thread and a rubber band.
The moving eye-square is on the one side connected to the moving servo motor. The other side is fixed with a rubber band, so it gets drawn back if the servo releases. Be sure to put some wood over the backside so the eyes can still move, but also don’t fall out to the back!
Now, wire and program the arduino with the code oftware you can find in the Github repository below. A description of how the servo(s) are wired can be found in the code. We used a 12V / 2A wall plug to power the whole thing.
You are done! Ready to get haunted!
This university project led by Charles Matthews works on the connection of classic traditional serial composition – in this case gamelan music – and robotic Gamelan instruments. The actuators are driven electronically. Charles also developed a software called “Pipilan” which was written in Max/MSP. With this he controls the gamelan Gongs. From our understanding the software is an intelligent system which lets users interact with the robotic instruments by entering single set of notes. These are than merged into a constant gamela-music like flow.
The Augmented Gamelan project was set up to explore the combination of gamelan and electroacoustic music, with a focus on the way the instruments are traditionally played. The sound of this percussion ensemble from Indonesia is broken down, extended and warped through custom software and speakers placed amongst – and sometimes attached to – the instruments. The repertoire is based on traditional material and may be played in a wide range configurations to adapt to the space and context of performance. Many pieces also use traditional vocals including macapat (Javanese sung poetry).
For the interactive drum robot installation “MR-808 Interactive” we need interfaces that control this art installation. We choose Nexus 7 2013 (second version) Tablets as they are cheap (ca. 120€ at Ebay) and easy to use. On them we open a web-based drum sequencer that controls the physical moves of the robot in realtime. (more…)
Steam Machine Music is a homebuilt mechanical instrument made mostly from vintage Meccano parts. The instrument is driven by a steam engine that provides the whole instrument with energy.
The TLC 5940 is an awesome stand-alone 16 channel PWM chip, which can control e.g. 16 LEDs and is programmable via the SPI Bus. There is plenty of good code for connecting this LED Driver chip to the arduino.
I had the problem that I wanted to connect a 3W white LED and thus needing a high-current output for the TLC 5940. The TLC can drive 130mA per channel. The 3W LED has 0.25A @ 12V. I blogged about this before and there are different approaches:
- Connecting more than one outputs in parallel to the high power LED as proposed by TI in this PDF. One output can drive 130mA and so you can add them up.
- Connecting a N-Channel Mosfet (BUZ 11 (old!), IRLZ34N, NDS355) directly and using a pull-up resistor. The TLC is a current sink, meaning that its driving the load (e.g. LED) always to ground. Its working, but you have to invert the PWM in software (Full PWM = No Mosfet Output und visa verse).
One Version which I want to present here is to add an additional transistor like the BC547 to invert the TLC PWM signal and make it useful for driving the MOSFET directly!.
In the circuit you see the TLC on the left side and some more low power LEDs. Then you have the MOSFET circuit on the right. The high Power LED (not in the diagram) is connected to VCC (+12V) and the MOSFET drives it to ground when switched on.
Lets go! When the TLC channel is off, the Transistor – a SMD variant of the famous BC547 – is switched through, pulling the Mosfet to ground: the LED is off.
If the TLC now starts working it pulls the Transistor to ground, leaving a positive potential at the ate of the Mosfet, which results in a lightening LED.
Sometimes it is not possible to stuff all the hardware for a live performance into a Macbook. Then you need a real PC. But it shall be transportable. Without too many cables. Easy to setup. With everything insode .. well, like a macbook.
For our glitch robot project we needed a PC to handle the video date. And so we build our OWN laptop!
I recently made an redesign of some parts of our Glitch Robot Installation. A wonderful example of the capabilities of 3D-printing which we are using so often. Designed one year ago, I just had to press “print” to reprint the broken parts.
‘Madcam‘ is an open frameworks (C++) based project for mixing USB Web Cameras (e.g. the 10$ cheap PS3-Eye web cam) im realtime. Why this is awesome? Its usually hard and/or expensive to mix many video signals in realtime and display them side by side. We found a way to make it cheap, quick and reliable!
The project is a visual extension for another awesome project called “Glitchrobot” where Robots are used to make electronic music, but thats another issue. Lets start!
The goal is set up an VJ setup which is based on live webcam material. One webcam? – Boring! 10 Webcams? – “Unlimited” fun! (more…)