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Drum Kit Kit 

Make] Projects 

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build, hack, tweak, share, discover,- 

Drum Kit Kit 

Written By: SpikenzieLabs 


Sandpaper (1) 
Scissors (1) 
Soldering iron (1) 
Tin snips (1) 
Wire cutters (1) 


Drum Kit Kit (1) 

comes with four piezo sensors, PCB and 
other parts needed to make it work with 
the Arduino as a mini shield. 


to connect piezos (speaker style wire is 


Foam (1) 

• Mouse pad (1) 

Metal sheet (1) 


Solder (1) 



The kit contains the electronic parts required to make a drum kit. This includes the circuit 
board, resistors, diodes and pins. You supply the Arduino and the material to make the 
actual drum pads. Below you will find easy instructions for making traditional-looking drum 
pads, but you could also stick the piezo elements (the parts that sense the hits on the drum) 
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Drum Kit Kit 

to many different surfaces. Imagine playing your desk, lamp and telephone! 

Step 1 — Build the circuit. 

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• Remove the paper from the resistors and the diodes. 

• Bend all of the resistors and diodes like the photo. 

• Only use your fingers to bend the leads against the part's body. If you use a tool or a table 
top you may crack the part. 

• Push all of the resistors and diodes into the PCB, in the spaces marked R1 to R6 and D1 
to D6. All of the resistors and all of the diodes are the same. 

• NOTE: The black band on the diode must be oriented to the side with the white 
band on the PCB printing (down when the text is readable, see left). 

• Resistors may go either way. 


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Drum Kit Kit 

Step 2 

• Flip the board over and heat up your soldering iron. You may want to tape the parts onto 
the board, so they don't fall out when you flip it. 

• I prefer to tape the leads rather then bending them. When you bend them you could cause 
a short circuit, if you aren't careful. 

• Solder all the leads. 

• Using wire snips, trim all of the leads so that they don't stick out too much. 



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Drum Kit Kit 

Step 3 

• Push the male pins through the PCB from the bottom and hold them there with some tape. 

• Solder them in place from the top. 

• Your mini Arduino Drum Kit shield is now ready. 

• To connect your drum pads to the Drum Kit PCB see step 16 in the making pads section 

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Drum Kit Kit 

Step 4 — Build the drum pads. 

• Building a drum pad in essentially just putting together a sandwich of layers with a sensor 
in the middle of it. The top layers protect the sensor from damage and reduce the amount 
of noise from the drum stick hitting the sensor. The middle layer is a piece of metal that 
helps transmit the shock from the stick into the piezo sensor. The bottom layers help keep 
the drum pad from rattling on the table and also give it a solid base to mount it to 

• The drum pads shown here were all assembled onto one piece of 1/4" plywood and the 
pads were made small so that it could be used as a desktop model. You may build yours 
much bigger, with individual pads. You could even get extra piezos and experiment with 
different constructions. 

• Draw circles the on the metal sheet. You choose the size. 

• Cut out the circles that you drew on the metal sheet with the tin sips. 

• Wear safety glasses and gloves! 


• Repeat for all of the drum pads. Careful; some of the edges may be sharp. 

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Drum Kit Kit 

Step 5 

• Rough up the center of each disk on one side. This is were you will glue the piezo sensor. 

• Mix equal parts of epoxy on a scrap of something. Mix well, and don't get dirt into the glue, 
because you will want the piezo to be glued down perfectly flat. 

• (Hot glue also works, but it is harder to get flat.) 
Step 6 

• Apply a thin amount of glue to the rough area on the metal. 

• Press the piezo into the glue with the wires and light-colored side up. 

• Put these aside until the glue is hard. 

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Drum Kit Kit 

Step 7 

• Make lengths of wire to connect the drum kit to the piezos. 

• It is best to use two colors, because it is important that the red and black wires of the 
piezo go to the correct places on the drum kit. 

• To make soldering the wires to the piezos easier, tin the wires. To tin the wires, 
hold your soldering iron on the wire for a moment then melt solder onto the end of 
the wire so that it is shiny and silvery. 

• Do the same for the red and black wires connected to the piezos. 

• Solder one wire at a time. Place the tinned end next to the tinned end of the wire from the 
piezo and heat them with the soldering iron. The solder should easily melt and stick the 
wires together. 

• Hold the joint still until the solder is cold, for a good connection. 

• The joint between the wire and the piezo is quite weak. To strengthen it I recommend using 
heat-shrink tubing. You may also use electrical tape or hot glue. 

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Drum Kit Kit 

Step 8 

• Using the same diameter circle that you used in Step 4 draw circles onto the bottom foam 
and the mouse pad. 

• Using a pair of scissors, cut out the circles that you just drew. 

• Using spray glue, coat one side of the base foam. Then place it, glue side down, onto the 
surface where you would like to build your drum pad. Press. 

Step 9 

• Decide how you would like to route your wire before you complete this step. It will be 
harder to move the wires afterwards. 

• Using the same technique as in Step 8, apply glue to the bottom of the metal plate (the 
side with the piezo) and glue it on top of the foam. 

• Now glue the mouse pads on top of the metal plates. 

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Drum Kit Kit 

Step 10 

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Drum Kit Kit 

• At the bottom edge of the Drum Kit 
PCB, there is space to connect six 
drum pads. Each drum pad should 
go to one of the sets of solder 
pads, with the wire from the red 
lead of the piezo to the "+" solder 
pad and the black wire from the 
piezo to the other. 

• NOTE: Polarity is important. 
Connect only wire from the 
red wire of piezo to a "+" solder 

• To connect the drum pads to the 
Drum Kit, you have some choices. 

• 1. Wire the pads directly, and 
solder the wires to the Drum Kit 
PCB for a permanent 
connection. (Easiest and most 
solid, but hard to change set-up 

• 2. Use a combination of male 
and female headers soldered 
both to the end of your wires and 
the Drum Kit PCB so that you 
can disconnect the pads and 
move them about. (Convenient 
but may shake off if it is in a 
location that receives vibrations 
from the drum pads.) 

• 3. Solder to RCA jacks and use 
other RCA jacks at the drum pad 
end, with an RCA cable between 

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Drum Kit Kit 

Step 11 — Use the Drum Kit Kit with an Arduino. 

• Download, install and test the Serial MIDI Converter software with your Arduino. (Testing it 
here will help so you will know that the MIDI interface is working.) 

• NOTE for people wanting to use a hardware MIDI interface: If you have a 
hardware- based MIDI shield, you could also use it with the Drum Kit Kit. Follow the 
directions that came with it. Most often, you will simply use the TX serial pin of the Arduino 
and connect it to the point where the shield gets the serial data to send out over the MIDI 
cable. You may also have to change the baud rate in the sketch. 

• Connect the Drum Kit to your Arduino. The solder pads where the drum pads' wires 
connect will hang off the bottom edge of the Arduino and the six pins on the Drum Kit will 
fit into the six analog pin holes on the Arduino, with the two other pins fitting into the two 
ground pin holes. 

• Download the Drum Kit Kit Arduino sketch . 

• Compile and upload the sketch to your Arduino. 

• Start the Serial MIDI Converter software, choose the serial port that your Arduino is using 
and the virtual MIDI ports that you set up earlier. 

• Start your music software and hit some drums! 

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Drum Kit Kit 

Step 12 — Tune your drum kit. 

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Drum Kit Kit 

unsigned char Faottotft[6] ■ {52,16,66,63,46,65}; 
it it PadCutOff [6] - {699,688,600,660,680,680}; 

Int tta*PloyTi»er>] = {98,96,98,90,96,90}: 
Jdefin* kidichannel &; 
boolean Velocityf log - true} 

// NIDI rtote* fro* 6 to 127 (Mid C . 68) 
// ttifimuti Analog volue to caus« a drun hit 
// Cycles before a 2nd hit is at lowed 
// Mpl channel from 8 to 15 <*1 in "red 
// Velocity ON (trus) & r OFF (false) 

• The most common change the you 
will probably do to your Arduino 
Drum Kit sketch is change the 
musical note associated with each 
pad. You may want a particular pad 
to be a snare drum and another to 
be a cymbal, etc.; you decide. 

• The other type of tuning has to do 
with getting the best playing 
performance out of your 
configuration of drum pads. Since 
you will be making your own drum 
pads, some people will use harder 
foam than others, some people will 
place their pads closer together 
than others and in other cases the 
type or length of wire used to 
connect the pads will affect the 
way the drum kit plays. Here is an 
explanation of the different areas 
where you can tune your drum kit: 

• PadNote: These are the MIDI 
notes that will be played when a 
drum pad is triggered. They 
range from to 127, where 
middle C is the number 60. Do 
not use a value above 127. 

• PadCutOff : The Arduino reads 
analog values as a number from 
to 1023. When you hit a drum 
pad the piezo creates a voltage 
spike and ripple. We are reading 
the value of this voltage spike. 
The PadCutOff is the minimum 
value of this spike that we will 

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Drum Kit Kit 

accept as a drum hit. You can 
set it higher or lower. Lower will 
make more false triggers, but 
easier to make drum hits if your 
pads are thick. Higher will 
require you to hit the pads 
harder to make them sound, but 
you will get fewer false triggers 
from hitting a nearby pad if they 
are on the same surface. 

• MaxPlayTime: This is a delay 
based on the speed with which 
the Arduino executes the main 
program loop. This delay is 
intended to keep the kit from 
sounding multiple hits for one 
drum hit, since the Arduino is 
fast enough to read the same 
voltage spike a few times. If you 
are getting two or more hits 
when you hit the drum only 
once, increase this number. If 
there is too large a delay when 
you play a drum roll, then 
decrease this number. 

• midichannel: This is simply the 
MIDI channel that will be 
sending the MIDI messages. 

• VelocityFlag: This is atrue-or- 
false setting. "Velocity" is a 
value that represents how hard 
you hit the drum pad. A higher 
velocity will produce a louder 
drum sound. If you want the 
drum pads to produce a louder 

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Drum Kit Kit 

sound when you hit them harder, 
set this flag to true; otherwise, 
set it to false. 

This project was featured in the MAKE School's Out! special issue. 

This document was last generated on 201 2-1 0-30 06:1 5:39 PM. 

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