hands-on Arduino introduction making a sequencer to send 3 channels of pulse signals to a drum chip (Arduino based dsp-D8) designed for 2 workshops at Sonar Hong Kong, 17 March 2018

1. Arduino workshop 2018Arduino workshop 2018
Hands-on Arduino:
8-step drum sequencer
Tom Tobback
www.cassiopeia.hk
2018

2. Arduino workshop 2018
some of Tom’s projects
cassiopeia.hk/category/projects/

3. Arduino workshop 2018
Before we start… check the connection between your
Arduino board and your laptop:
● plugin your Arduino board USB cable into your laptop
● open Arduino IDE software (www.arduino.cc)
● open the Blink sketch from File>Examples>Basic
● pick the correct port from Tools>Serial Port
● pick the correct board type from Tools>Board “Uno”
● hit ‘upload’ to test the connection
● look for ‘Done uploading’ and check if the onboard LED
is blinking

4. Arduino workshop 2018
Arduino: what is it?
Arduino is an open-source
electronics prototyping platform
based on flexible, easy-to-use
hardware and software
It is intended for artists, designers,
hobbyists and anyone interested in
creating interactive objects or
environments
• sensors
• sound
• light
• wifi
• ...

5. Arduino workshop 2018
Our program for today
terminology 4
software 2
basic electronics 4
projects 20+
blink
sequencer
Slides PDF:
Desktop/workshop/SonarHK2018-arduino-slides.pdf

6. Arduino workshop 2018
Arduino terminology
software:
• IDE
• web editor
• sketch
• uploading
• syntax
hardware:
• board
• microcontroller (mcu)
• pin headers
• input
• output
• digital/analog
• breadboard
• jumper wires
• components

7. Arduino workshop 2018
Arduino vs Raspberry Pi
➔ looks similar
➔ similar price
➔ micro-controller vs
mini-computer
➔ Arduino: IO
➔ Pi: OS
Other popular platforms:
ESP8266, Particle Photon, micro:bit

8. Arduino workshop 2018
Arduino boards
➔ many official boards
➔ different sizes
➔ different connections
➔ use same code
➔ mostly compatible
➔ extra functions via shields

9. Arduino workshop 2018
Arduino UNO

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Arduino-style boards
➔ many copies
➔ many improvements
➔ extra functions included
(Wifi, GPS, motor, Ethernet,...)
➔ use same code
➔ mostly compatible
➔ cheaper!

11. Arduino workshop 2018
Arduino software: IDE
➔ Integrated Development Environment
➔ Write sketch -> upload to board
➔ Useful examples
➔ ‘Libraries’ to make our life easier
Always make sure to pick the correct BOARD
➔ Connect using USB cable, pick correct PORT
➔ Upload sketch
➔ Check output of Serial Monitor
➔ Save your sketches..

12. Arduino workshop 2018
Arduino software: Web Editor
Same functionality with:
➔ Browser based editor (needs login)
➔ Accessible from any computer
➔ Storage in the cloud
➔ Need to sign up for username
➔ Need to install the Arduino Create plugin for upload

13. Arduino workshop 2018
Basic electronics
➔ DC direct current vs alternating current AC
➔ voltage: volts 5V (usb), 3V3, 9V
➔ current: milli ampere 40 mA = 0.04 A
➔ power: watts 1-2 W (USB limit)
➔ resistors: reduce voltage
➔ diodes: one-way + light
➔ capacitors: small battery
➔ schematics

14. Arduino workshop 2018
Basic electronics
DIGITAL: on/off
1/0
true/false
high/low
0V/5V
ANALOG: variable 0->5V
Ohm’s law: U = I * R
Kirchoff’s laws:

15. Arduino workshop 2018
From prototype to product

16. Arduino workshop 2018
Breadboard = connections

17. Arduino workshop 2018
Breadboard power rails
5V to red line
GND to blue line
Optional:
connect to other side

18. Arduino workshop 2018
Our project

19. Arduino workshop 2018
Arduino projects for today
➔ Blink: the ‘hello world’ of Arduino pinMode
digitalWrite
delay
➔ Read push button digitalRead
➔ Read potentiometer analogRead
Build the step sequencer
Connect to drum PCB

20. Arduino workshop 2018
Arduino: ‘blink’ sketch
/*
Blink
Turns on an LED on for one second, then off for one second, repeatedly.
*/
// the setup function runs once when you press reset or power the board
void setup() {
// initialize digital pin 13 as an output.
pinMode(13, OUTPUT);
}
// the loop function runs over and over again forever
void loop() {
digitalWrite(13, HIGH); // turn the LED on (HIGH is the voltage level)
delay(1000); // wait for a second
digitalWrite(13, LOW); // turn the LED off by making the voltage LOW
delay(1000); // wait for a second
}
initialisation
setup { }
loop { }
change these numbers and see what happens
‘upload’ after each change!
File>Open> “Desktop/workshop/blink1/blink1.ino”

21. Arduino workshop 2018
Arduino: blink
Blink: the ‘hello world’ of Arduino
220 ohm
LEDs short straight leg goes
into the blue line (GND)

22. Arduino workshop 2018
resistor colour code
220 ohm = 220 Ω
red red black black (brown)
10k ohm = 10,000 Ω
brown black black red
(brown)

23. Arduino workshop 2018
connect the drum PCB
8 inputs - power - speaker
power:
PWR+ goes to 5V (red line on breadboard)
PWR- goes to GND (blue line on breadboard)
speaker:
connect SPK+
and SPK-
BD = bass drum
SD = snare drum
CH = closed hi-hat
OH = open hi-hat
RS = rim shot
CL = clap
RD = ride
CR = crash

24. Arduino workshop 2018
connect the drum PCB
can also connect to amplifier or earphones with
3.5mm mini jack

25. Arduino workshop 2018
connect the drum PCB
drum triggered on
the falling edge
HIGH
LOW
drum sound
starts

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Arduino: button
[add this to setup]
pinMode(2, INPUT_PULLUP);
[replace loop with]
if (digitalRead(2) == LOW) {
digitalWrite(13, LOW);
}
else {
digitalWrite(13, HIGH);
}
which is same as:
digitalWrite(13, digitalRead(2));
INPUT_PULLUP:
● avoid ‘floating’ input status
● inverted logic: push = LOW

27. Arduino workshop 2018
Arduino: potentiometer
put the pot legs in
columns 8,10,12

28. Arduino workshop 2018
Arduino: potentiometer
[replace loop with]
void loop() {
digitalWrite(13, HIGH);
delay(10);
digitalWrite(13, LOW);
delay(analogRead(A0));
}
[analogRead returns 0->1023]put the pot legs in
columns 8,10,12

29. Arduino workshop 2018
Serial Monitor and Plotter
[add this line to setup]
Serial.begin(9600);
[modify loop to]
digitalWrite(13, HIGH);
delay(100);
digitalWrite(13, LOW);
Serial.println(analogRead(A0));

30. Arduino workshop 2018
Arduino: sound
[modify loop to]
digitalWrite(13, HIGH);
tone(3, 1000);
delay(100);
digitalWrite(13, LOW);
noTone(3);
delay(analogRead(A0));

31. Arduino workshop 2018
7 segment display
use 8 short wires
D13 to D6 (8 pins)
resistor from blue
line to column 3
10,11,x,12,13
9,8,x,7,6

32. Arduino workshop 2018
7 segment display
File>Open> “Desktop/workshop/seq8-template1/seq8-template1.ino”
this sketch has helper functions in tab “sonar.h”
add in loop:
showStep();
delay(analogRead(A0));
increaseStep();

33. Arduino workshop 2018
7 segment display + pulse
modify loop:
showStep();
digitalWrite(13, HIGH);
delay(10);
digitalWrite(13, LOW);
delay(analogRead(A0));
increaseStep();
pulse delay
showStep increaseStep

34. Arduino workshop 2018
connect clock to drum PCB
add a long wire from the breadboard
(dot of segment display, column 5) to
the drum PCB, any input e.g. CH
CH

35. Arduino workshop 2018
Add 4 control buttons
use the 4-pin ribbon cable
A1 to A4
X

36. Arduino workshop 2018
Add 3 drum LEDs
use the short 3-pin ribbon cable
D5 to D3 LED’s short straight leg goes
into the blue line (GND)
X

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LED pulses
modify loop:
showStep();
sendPulses();
delay(analogRead(A0));
increaseStep();
pulse delay
showStep increaseStep
X

38. Arduino workshop 2018
Add 3 outputs to drum PCB
use the long 3-pin ribbon cable to BD SD OH
X

39. Arduino workshop 2018
play/step mode
modify loop:
showStep();
if (playMode()) {
sendPulses();
delay(analogRead(A0));
} else {
editStep();
}
increaseStep();
add a wire from D2 to
GND (blue line)

40. Arduino workshop 2018
edit step mode
with the D2 wire connected, move to next step with button 4
the LEDs show
which drum is
active for that step
use the 3 buttons
to toggle on/off

41. Arduino workshop 2018
hack it :-)
● change the 3+1 output wires to different drum sounds
● use a wire connected to GND to trigger other drum
sounds while the sequence is playing
● change the code to 6 steps
● replace the drum samples in the drum chip with your own
samples
● build a box for this sequencer
● ...

42. Arduino workshop 2018
drum chip
Arduino chip (Atmega328p)
Open Source code “dsp-D8” from
https://janostman.wordpress.com/2016/01/03/the-dsp-d8-drumchip-source-code/
(minor modifications)

43. Arduino workshop 2018
Arduino: suppliers
ONLINE
➔ Official Arduino shop: http://arduino.cc/
great documentation, projects, forum
➔ Seeedstudio: http://www.seeedstudio.com/depot/
➔ Telesky: https://telesky.world.tmall.com/
➔ Adafruit: http://www.adafruit.com/ great documentation
IN HONG KONG - Apliu St
➔ WECL http://www.weclonline.com/wecl_eng/index.html

44. Arduino workshop 2018
Arduino: kits
➔ Seeedstudio Sidekick
Arduino kit
➔ Arduino Starter Kit

45. Arduino workshop 2018
Dimsum Labs
the hackerspace of HK www.dimsumlabs.com/
community of technology enthusiasts
space for creativity in Sheung Wan
Tuesday evening HackJam
www.facebook.com/groups/hackjamhk/

46. Arduino workshop 2018Arduino workshop 2018
Thank you
www.cassiopeia.hk
Happy tinkering!