Cassiopeia Ltd - standard Arduino workshop

transcript

standard Arduino workshop 2017

Hands-on Arduino introduction

Tom Tobbackwww.cassiopeia.hk2017

some of Tom’s projectscassiopeia.hk/category/projects/

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

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

Our program for today

terminology 4software 2basic electronics 4projects 20+

metronometheremin

Arduino terminology

software:• IDE• web editor• sketch• uploading

hardware:• board• microcontroller (mcu)• pin headers• input• output• digital/analog• breadboard• jumper wires• components

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

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

Arduino UNO

Arduino-style boards

➔ many copies➔ many improvements➔ extra functions included

(Wifi, GPS, motor, Ethernet,...)➔ use same code➔ mostly compatible➔ cheaper!

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..

Arduino software: Web EditorSame 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

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

Basic electronicsDIGITAL: on/off

1/0 true/false high/low 0V/5V

ANALOG: variable 0->5V

Ohm’s law: U = I * R

Kirchoff’s laws:

From prototype to product

Breadboard = connections

Breadboard power rails

5V to red lineGND to blue line

Optional:connect to other side

Breadboard

Arduino projects for today➔ Blink: the ‘hello world’ of Arduino pinMode

digitalWritedelay

➔ Read push button digitalRead➔ Read potentiometer analogRead➔ Output to Serial Monitor Serial.print➔ Buzzer music tone➔ Potentiometer + blink + buzzer = metronome➔ Read photoresistor/LDR➔ Fading (PWM) analogWrite➔ Input to Serial Monitor Serial.read

Arduino: blinkBlink: the ‘hello world’ of Arduino

220 ohm

resistor colour code

220 ohm = 220 Ωred red black black (brown)

10k ohm = 10,000 Ωbrown black black red (brown)

Arduino: ‘blink’ sketch/* Blink Turns on an LED on for one second, then off for one second, repeatedly. Most Arduinos have an on-board LED you can control. On the Uno and Leonardo, it is attached to digital pin 13. If you're unsure what pin the on-board LED is connected to on your Arduino model, check the documentation at http://www.arduino.cc This example code is in the public domain. modified 8 May 2014 by Scott Fitzgerald */

// the setup function runs once when you press reset or power the boardvoid setup() { // initialize digital pin 13 as an output. pinMode(13, OUTPUT);}

// the loop function runs over and over again forevervoid 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 { }

bonus:attach a second LED to pin12 doing exactly opposite of LED on pin13

Arduino: RGB LED blinkRed Green Blue = primary colours (additive)

V = common negativeR = red positiveB = blue positiveG = green positive(including resistors)

use digitalWrite to mix colourse.g. on pin 10, 11, 12

Arduino: RGB LED blink

[optional] Arduino: button

boolean button_pressed = false;---pinMode(2, INPUT);---button_pressed = digitalRead(2);

if (button_pressed == true) { digitalWrite(13, HIGH);}else { digitalWrite(13, LOW);}

use pinMode(2, INPUT_PULLUP);or: pull-down resistor (e.g. 10kΩ)

Arduino: potentiometer

Arduino: potentiometerint pot_value; [VARIABLE]

[SETUP][LOOP]pot_value = analogRead(A0);

[change your delay to:]delay(pot_value);

[analogRead returns 0->1023]

5k ohm

Arduino: Serial Monitor[SETUP]Serial.begin(9600);

[LOOP][try one by one:]Serial.print(“hello”);[or]Serial.println(“hello”);[or]Serial.print(“pot value: “);Serial.println(pot_value); bonus:

print description of your program on startup and format output with \t

Arduino: Serial Plotter[LOOP]Serial.println(pot_value);

Arduino: metronomeBlink with variable speed, and bpm in serial monitorHow?

read pot_value (analogRead)print pot_value (Serial.print)calculate beats per minute (=)print BPM (Serial.print)

LED ON for 100ms (digitalWrite)LED OFF for variable time: pot_value

100ms variable pot_value

ON OFF

Arduino: metronometotal ‘beat’ length = 100ms ON + variable OFFbeat_length = 100 + pot_value

beats per minute = (60 * 1000) / beat_length

BPM will vary from 53 to 600

100ms variable pot_valuebonus:attach a second LED to pin12 doing exactly opposite of LED on pin13

ON OFF

total beat length

Arduino: metronome

‘int’ type does not work with large numbers(larger than around 32000, 16 bits)type to use = ‘long’

long bpm;[SETUP][LOOP]

bpm = (60 * 1000L) / (100 + pot_value);

bonus:format your output with \t

Arduino: soundPiezo buzzer = speaker

SYNTAX:tone(pin, freq);tone(pin, freq, duration);noTone(pin);

[SETUP][LOOP]tone(3, 261); [put in correct place!]noTone(3); [put in correct place!]

Arduino: metronome + sound

● LED on and beep (100ms) + LED off and no beep● variable speed with potentiometer● serial monitor BPM

frequency examples (Hz):C 261D 293E 329G 392

bonus:try different frequencies

Arduino: light dependent resistor

LDR or photoresistor = variable resistor, similar to potentiometer -> analogReadvoltage divider: sum=5V and analog input sees 0->5V

1K ohm

int ldr_value;[SETUP][LOOP]ldr_value = analogRead(A1);Serial.println(ldr_value);

check on the Serial Monitor for min, max values of the LDR

how to go from e.g. 50-500 values to 200-5000Hz frequencies? use ‘map’ function

int freq;

[SETUP][LOOP]

freq = map(ldr_value, 50, 500, 200, 5000);

tone(3, freq); [just update this line]

SYNTAX: map(value, fromLow, fromHigh, toLow, toHigh)

Basic theremin

Arduino: basic theremin sketchint pot_value;int ldr_value;int freq;long bpm;

void setup() {pinMode(13, OUTPUT);Serial.begin(9600);

void loop() {pot_value = analogRead(A0);bpm = (60 * 1000L) / (100 + pot_value);

ldr_value = analogRead(A1);freq = map(ldr_value, 50, 500, 200, 5000);

Serial.print(“BPM: “);Serial.println(bpm);

digitalWrite(13, HIGH);tone(3, freq);delay(100);

digitalWrite(13, LOW);noTone(3);delay(pot_value);

Advanced theremin

1. Use a pentatonic scale with a lookup table= table of frequencies on a pentatonic scale, accessible by index

2. Add a 2 step ‘sequencer’

1 loop = constant base note + variable note on second beat

100ms variable pot_value 100ms variable pot_value

base note silence variable pentatonic note silence

Pentatonic theremin

Pentatonic scale with a lookup table

int pentatonicTable[50] = { 0, 19, 22, 26, 29, 32, 38, 43, 51, 58, 65, 77, 86, 103, 115, 129, 154, 173, 206, 231, 259, 308, 346, 411, 461, 518, 616, 691, 822, 923, 1036, 1232, 1383, 1644, 1845, 2071, 2463, 2765, 3288, 3691, 4143, 4927, 5530, 6577, 7382, 8286, 9854, 11060, 13153, 14764 };

OLD: freq = map(ldr_value, 50, 500, 200, 5000);

NEW: freq = pentatonicTable[map(ldr_value, 50, 500, 20, 45)];

2 step sequencer theremin

1 loop = constant base note + variable note on second beat

tone(3, 206); noTone(3); tone(3, freq); noTone(3);delay(100); delay(pot_value); delay(100); delay(pot_value);

Now you can add steps, change length of steps etc...

100ms variable pot_value 100ms variable pot_value

base note silence variable pentatonic note silence

Arduino: AnalogWrite (PWM)

Analog input = 0 to 5 VArduino does not outputa real analog signal (0-5V)

analogWrite(pin, value);PWM = Pulse Width Modulation

only available on pins 3,5,6,9,10,11can use this to fade LED

values from 0 to 255 (8 bits)

Arduino: AnalogWrite (PWM)‘for’ structure = loop for X times

Open sketch: Examples > 03.Analog > Fading[change your breadboard LED to pin 9] // fade in from min to max in increments of 5 points: for(int fadeValue = 0 ; fadeValue <= 255; fadeValue +=5) { // sets the value (range from 0 to 255): analogWrite(ledPin, fadeValue); // wait for 30 milliseconds to see the dimming effect delay(30); }

Arduino: input via Serial Monitortop box of Serial Monitor = inputsend data from computer to Arduino - ASCII format (bytes)

Arduino: input via Serial MonitorLet’s read a number 0-9 for intensity of LED[remove all commands from loop]

int brightness;[SETUP]Serial.begin(9600);[LOOP]if (Serial.available()) { brightness = Serial.read(); Serial.print("Arduino received: "); Serial.println(brightness);}[switch to ‘No line ending’ at bottom of Serial Monitor?]

Arduino: input via Serial Monitorfor analogWrite we need to map the brightness from 48-57 (ASCII for 0 to 9)to 0-255 for analogWrite (0% to 100%)

[add this line in the loop]analogWrite(ledPin, map(brightness, 48, 57, 0, 255));

Arduino: suppliersONLINE➔ 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➔ Tell How http://tellhow-tech.com/

Arduino: kits

➔ Seeedstudio Sidekick Arduino kit

➔ Arduino Starter Kit

Dimsum Labs

the hackerspace of HK www.dimsumlabs.com/ community of technology enthusiastsspace for creativity in Sheung Wan

Tuesday evening HackJamwww.facebook.com/groups/hackjamhk/

Thank you

www.cassiopeia.hk

Happy tinkering!

Cassiopeia Ltd - standard Arduino workshop

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