This Instructable aims to easily explain how to build a launchpad using simple everyday items and a MaKey MaKey Arduino hooked up to your computer.For this, you will need the following:
- 600mm x 600mm sheet of acrylic
- A MaKey MaKey chipboard (you can buy these from http://littlebirdelectronics.com.au/products/make...
- Jump leads
- Aligator clips
- 1m bare addressable RGB LED strip (it is EXTREMELY IMPORTANT that these are INDIVIDUALLY ADDRESSABLE. if they are not the lights will NOT WORK!)
- 2m networking cable
- Wire cutters and strippers
- Soldering iron and solder
- 5 Volt power supply
- power adaptor
- 1000 micro-pharad capacitor
- 300 ohm resistor
- Copper tape
- Plain sticky tape
- Gaff tape
- White tracing paper
- Black cardboard
- Lots of cardboard! (make sure there is some big enough to make a base that is the same size as the acrylic)
- Packaging tape and electrical tape
- Aluminium foil
- small container to hold items
- An Apple Macintosh computer or laptop
- Downloadable content (SparkFun ‘Adafruit Neopixel’ library, Hairless MIDI.app, Ableton 9 Live.app and the Ardunio.app) - The codes for the arduino app can be found in the zip files above (also included is the adafruit pixel library)
**Please note that this task will take TIME and PATIENCE! it is not something that can be achieved overnight.
Credit to jdeboi for her MaKey MaKey Monome - this instructable has been adapted to run a similar code as a launchpad instead of a monome
Step 1: Prepare
The first step is to prepare your items.
Using your marker, draw a grid over the acrylic. This grid will be 7 x 7, each square being 3 inches. Leave a 2.5 inch border around the edges of the acrylic (this is more for design purposes but you will thank me later).
Once all of your pieces are outlined, cut your LED strip along the marked line and put these in a small container as to not to lose them.
Now to start moving onto the fun!
Step 2: The Base
The base will be the most important part in terms of the design of your launchpad.
Now that your base has been outlines, grab your Blu-tak and tack one LED light per grid. Try to get these in the centre of each grid section, and these are going to zig zag across the board. How? See the small arrows on the LED near the DO pin? they need to zig zag so that there is a constant flow in and out of the lights. If this is done incorrectly, you will blow the light.
Once these have been put into place, begin to strip your network cable and unravel the wires inside. The reason behind using networking cable is that solid core wire is easier to solder (especially for beginners). Cut this so that the wires easily reach between two lights, which should be about 3 inches long per wire. You will need 3 wires per side of the light, one for data, earth and power. After these have been cut and stripped, its time to solder them on. Again, it is extremely important to solder these to the right patch (data in - data out, 5V - 5V, GND - GND) or you will blow the lights.
Now all the wires have been soldered on, its time to attach the capacitor, resistor and power supply. The power supply will attach to the power adaptor, with an earth and power cable to run from the adaptor. Cut 2 sets of wires at 3 inches each, one set needs to go to power and earth from the adaptor, the other end needs to be soldered to the other wires with the capacitor. The end of the second wires then need to be soldered to the first light pad. For data, solder one resistor to one end of the jump cable, and the other plug into the D0 PIN of the MaKey MaKey board. Grab another wire and solder one end to the other end of the resistor and the other side of the wire to the LED.
Step 3: Lattice
The next step is to isolate the lights with the cardboard. Cut the cardboard so that it sits along the grid (so each strip will be 600mm long, with 2.5inch edges and slots 3 inches apart. The height of the strip should be about 4.5inches). Cut enough to fill the grid so each light is isolated. Once this lattice has been cut, add a trim around the box to house it and tape it together. Cut a hole for the power adaptor to fit and another for the USB cable for the MaKey MaKey. We are going to house the MaKey MaKey inside that 2.5inch trim of the box. Make sure it is front face down, as we need all the back pins later on.
Step 4: The Touchscreen
The touch screen is the part that connects the lights and your touch to trigger sounds.
Using the marks drawn in step 1, lay the copper tape in columns, and leave about an inch hanging off the screen. Later on, we will connect wires to this excess amount of tape. You need to lay plain sticky tape over the cross sections where the rows will intersect. This is important as it isolates each column to create a unique number where the sections meet. This in turn creates more inputs on the MaKey MaKey to take it from 16 to 49.
After the grid is set, we need to connect each row and column together. See below for the pattern used. By laying the copper tape across like this, we create the unique number were the column and row intersects.
Once this has been completed, use the black cardboard to create a nice border. It is an idea to use Blu-tak to connect it to the front and plain tape on the back of the acrylic. Make sure you leave holes so that the copper tape can reach through and connect later on the back side. Then, lay the white tracing paper on the back of the screen. This will diffuse the lights once this is laid onto the base of the launch pad.
Once these steps are completed, lay the screen on top of your base.
Step 5: Wiring and Testing
Now its time to test everything before we secure it in place.
Connect alligator clips to all rows and columns. You will need to connect to some jump wires to access other inserts on the MaKey MaKey so have these handy. See the diagram below to see how to connect the wires up (this is not a set way but will help to have something written down for a little later on). You will also need a ground cable to connect yourself to the launch pad.
Connect the MaKey MaKey to your computer and download the SparkFun ‘Adafruit Neopixel’ library. You will need this to test and code your lights. Open the Arduino.app and run the “strandtest” sketch. All the lights should light up and cycle through different colours and patterns. While this is running, make sure your grid on the touch screen matches up to the grid on the individual lights and tweak the lattice if needed.
Open up Ableton Live 9 and start to map the touchscreen through hairless MIDI to Ableton. You may find that some grids don't map to Ableton at all, so you might need to add some aluminium foil underneath the connections on the copper tape to help with conductivity.
Step 6: Tidy and Perform
The last step, if everything is working well, is to tape it all into position with some Gaff tape, and start your sample bank in Ableton.
The ableton file i have used is in the zip file below