arduino basics
TRANSCRIPT
LTKA Labs
Arduino BasicsEueung Mulyana
http://eueung.github.io/ET3010/arduinoET-3010 | Attribution-ShareAlike CC BY-SA
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Outline
Short Intro
Quick Start
Networking
MQTT
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Short Intro
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ArduinoAn open-source hardware and software platform for building
electronics projects.
Arduino is an open-source electronics platform based oneasy-to-use hardware and software. It's intended foranyone making interactive projects.
Arduino senses the environment by receiving inputs frommany sensors, and affects its surroundings by controllinglights, motors, and other actuators.
You can tell your Arduino what to do by writing code inthe Arduino programming language and using theArduino development environment.
Several Arduino-Board variants exist e.g.: UNO, NANO,MEGA, DUE, YUN, etc.
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Quick Start
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This ChecklistPlease:
UNO BoardCompatible +Acessories
Components +Wires
ARDUINO IDE
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Tools - Config12 / 44
Sketch Upload13 / 44
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Project #1
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L
5V A0
ANALOG IN
AREF
1
GND
TXRX
RESET
3V3
A1
A2
A3
A4
A5
VIN
GND
GND
DIGITAL (PWM= )
Arduino TM
IOREF
ICSP
ICSP2
ON
POWER
01TX
0
RX0RESET
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1010
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A A
B B
C C
D D
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F F
G G
H H
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Fritzing Breadboard
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Project #1
D0/RX
D1/TXD
2
D3 PW
MD4
D5 PW
M
D6 PW
MD7
D8
D9 PW
M
D10 PW
M/SS
D11 PW
M/M
OSI
D12/M
ISO
D13/SCK
RESET
RESET2
AREF
ioref
A0
A1
A2
A3
A4/SD
A
A5/SCL
N/C
GND
3V3
5V
VIN
ArduinoUno
(Rev3)
21
211
2
12
13
2
Part1
LED1
Red (633nm)
R1100Ω
R210kΩ
S1R310kΩ
Fritzing Schematic
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Project #1 Sketchint inPin = 2; int outPin = 3; int potPin = A0;
int state = LOW; int reading; int previous = LOW;
long time = 0; long debounce = 1000;
int potVal = 0; int prevPotVal = 0;
void setup() { Serial.begin(9600); delay(500);
pinMode(inPin, INPUT); pinMode(outPin, OUTPUT); Serial.println("Program started ...");}
void loop() { reading = digitalRead(inPin);
if (reading && (millis() - time > debounce)) { if (previous == LOW) { Serial.println("[PHYSICAL] LED turned on"); state = HIGH; } else { Serial.println("[PHYSICAL] LED turned off"); state = LOW; }
time = millis(); digitalWrite(outPin, state); previous = state; prevPotVal = potVal - 10; } potVal = analogRead(potPin); if((state == HIGH) && (abs(potVal-prevPotVal)>4)){ analogWrite(outPin, potVal/4); Serial.print("[PHYSICAL] LED intensity "); Serial.println(potVal/4); prevPotVal = potVal; }}
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Serial Monitor20 / 44
Networking
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UNO + Ethernet Shield
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9 8 7 6 5 4 3 2
L
5V A0
ANALOG IN
ARE
F
1
GND
TXRX
RESET
3V3
A1
A2
A3
A4
A5
VIN
GND
GND
DIGITAL (PWM= )
Arduino TM
IOREF
ICSP
ICSP2
ON
POWER
01TX
0
RX0RESET
13 12 11 ETH 9 8 7 6 5
SDCS
3 2 01TX RXARE
F
GND
5V A0
ANALOG IN
TX
RX
RESET
3V3
A1
A2
A3
A4
A5
VIN
GND
GND
DIGITAL (PWM SPI )
SCL SDA
<
IOREF
ICSP
CS
< <
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Example #1 Web Server#include <SPI.h>#include <Ethernet.h>
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};IPAddress ip(192, 168, 0, 177);
EthernetServer server(80);
void setup() { Serial.begin(9600); while (!Serial) {}
Ethernet.begin(mac, ip); server.begin(); Serial.print("Server is at "); Serial.println(Ethernet.localIP());}
void loop() { // ...}
EthernetClient client = server.available(); if (client) { Serial.println("new client"); boolean currentLineIsBlank = true;
while (client.connected()) { if (client.available()) { char c = client.read(); Serial.write(c); if (c == '\n' && currentLineIsBlank) { client.println("HTTP/1.1 200 OK"); client.println( client.println("Refresh: 5"); client.println();
client.println("<!DOCTYPE HTML>"); client.println( for (int analogChannel = 0; analogChannel < 6; analogChannel++) { int sensorReading = analogRead(analogChannel); client.print("analog input "); client.print(analogChannel); client.print( client.println("<br />"); } client.println("</html>"); break; } if (c == '\n') { currentLineIsBlank = true; } else if (c != '\r') { currentLineIsBlank = false; } } } // while
delay(1); client.stop(); Serial.println("client disconnected"); }
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Test$> ping 192.168.0.177
Pinging 192.168.0.177 with 32 bytes of data:Reply from 192.168.0.177: bytes=32 time=2ms TTL=128Reply from 192.168.0.177: bytes=32 time=3ms TTL=128Reply from 192.168.0.177: bytes=32 time=2ms TTL=128Reply from 192.168.0.177: bytes=32 time=2ms TTL=128
Ping statistics for 192.168.0.177: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),Approximate round trip times in milli-seconds: Minimum = 2ms, Maximum = 3ms, Average = 2ms
Server is at 192.168.0.177new clientGET / HTTP/1.1Host: 192.168.0.177Connection: keep-aliveCache-Control: max-age=0Accept: text/html,application/xhtml+xml,application/xml;q=0.9Upgrade-Insecure-Requests: 1User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/Referer: http://192.168.0.177/Accept-Encoding: gzip, deflate, sdchAccept-Language: en-US,en;q=0.8
client disconnectednew clientGET /favicon.ico HTTP/1.1Host: 192.168.0.177Connection: keep-aliveUser-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/Accept: */*Referer: http://192.168.0.177/Accept-Encoding: gzip, deflate, sdchAccept-Language: en-US,en;q=0.8
client disconnected
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Browser
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Serial Monitor28 / 44
Example #2 Web ClientSingle Request
#include <SPI.h>#include <Ethernet.h>
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};IPAddress ip(192, 168, 0, 177);char server[] = "www.google.com";
EthernetClient client;
void loop() { if (client.available()) { char c = client.read(); Serial.print(c); }
if (!client.connected()) { Serial.println(); Serial.println("disconnecting."); client.stop();
while (true); }}
void setup() { Serial.begin(9600); while (!Serial) { }
if (Ethernet.begin(mac) == 0) { Serial.println("Failed to configure Ethernet using DHCP" Ethernet.begin(mac, ip); } delay(1000); Serial.println("connecting...");
if (client.connect(server, 80)) { Serial.println("connected");
client.println("GET /search?q=arduino HTTP/1.1"); client.println("Host: www.google.com"); client.println("Connection: close"); client.println(); } else { Serial.println("connection failed"); }}
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Example #3 Web ClientRepeated Requests
#include <SPI.h>#include <Ethernet.h>
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};IPAddress ip(192, 168, 0, 177);char server[] = "www.arduino.cc";
EthernetClient client;
unsigned long lastConnectionTime = 0; const unsigned long postingInterval = 10L * 1000L;
void setup() { Serial.begin(9600); while (!Serial) {}
delay(1000); Ethernet.begin(mac, ip);
Serial.print("My IP address: "); Serial.println(Ethernet.localIP());}
void loop() { if (client.available()) { char c = client.read(); Serial.write(c); }
if (millis() - lastConnectionTime > postingInterval) { httpRequest(); }}
void httpRequest() { client.stop();
if (client.connect(server, 80)) { Serial.println("connecting...");
client.println("GET /latest.txt HTTP/1.1"); client.println("Host: www.arduino.cc"); client.println("User-Agent: arduino-ethernet"); client.println("Connection: close"); client.println();
lastConnectionTime = millis(); } else { Serial.println("connection failed"); }}
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MQTT
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IoT ProtocolsThe IoT needs standard protocols. Two of the most promisingfor small devices are MQTT and CoAP.
MQTT gives flexibility in communication patterns and acts purelyas a pipe for binary data.
CoAP is designed for interoperability with the web.
Both MQTT & CoAP:
Are open standardsAre better suited to constrained environments than HTTPProvide mechanisms for asynchronous communicationRun on IPHave a range of implementations
See: MQTT and CoAP, IoT Protocols
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ArchitectureCoAP packets are much smaller than HTTP TCP flows. Bitfieldsand mappings from strings to integers are used extensively tosave space. Packets are simple to generate and can be parsed inplace without consuming extra RAM in constrained devices.
CoAP runs over UDP, not TCP. Clients and servers communicatethrough connectionless datagrams. Retries and reordering areimplemented in the application stack. Removing the need forTCP may allow full IP networking in small microcontrollers. CoAPallows UDP broadcast and multicast to be used for addressing.
CoAP follows a client/server model. Clients make requests toservers, servers send back responses. Clients may GET, PUT,POST and DELETE resources.
CoAP is designed to interoperate with HTTP and the RESTful webat large through simple proxies.
Because CoAP is datagram based, it may be used on top of SMSand other packet based communications protocols.
CoAPCoAP is the Constrained Application Protocol from the CoRE(Constrained Resource Environments) IETF group.
ArchitectureLike HTTP, CoAP is a document transfer protocol. Unlike HTTP,CoAP is designed for the needs of constrained devices.
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MQTTMQTT is a publish/subscribe messaging protocol designed forlightweight M2M communications. It was originally developedby IBM and is now an open standard. It was designed in 1999for use on satellites and as such is very light-weight with lowbandwidth requirements making it ideal for M2M or IoTapplications.
ArchitectureMQTT has a client/server model, where every sensor is a clientand connects to a server, known as a broker, over TCP.
MQTT is message oriented. Every message is a discrete chunk ofdata, opaque to the broker.
Every message is published to an address, known as a topic.Clients may subscribe to multiple topics. Every client subscribedto a topic receives every message published to the topic.
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MQTTFor example, imagine a simplenetwork with three clients and acentral broker.
All three clients open TCPconnections with the broker. ClientsB and C subscribe to the topictemperature .
At a later time, Client A publishes avalue of 22.5 for topic temperature .The broker forwards the message toall subscribed clients.
The publisher subscriber modelallows MQTT clients tocommunicate one-to-one, one-to-many and many-to-one.
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MQTT - Publish / Subscribe
The publish / subscribe (often called pub-sub) pattern lies at the heart of MQTT. It's basedaround a message broker, with other nodes arranged around the broker in a star topology.This is a very different model to the standard client/server approach, and at first it mightseem a little strange, but the decoupling it provides is a huge advantage in many situations.
Clients can publish or subscribe toparticular topics which aresomewhat like message subjects.They are used by the broker todecide who will receive a message.
Topics in MQTT have a particularsyntax. They are arranged in ahierarchy using the slash character(/) as a separator, much like thepath in a URL. So a temperaturesensor in your kitchen mightpublish to a topic likesensors/temperature/home/kitchen.
See: Zoetrope
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That's all for now..
Enough talkingLet's get our hands dirty!!
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Project #2
13 12 11 10
9 8 7 6 5 4 3 2
L
5V A0
ANALOG IN
AREF
1
GND
TXRX
RESET
3V3
A1
A2
A3
A4
A5
VIN
GND
GND
DIGITAL (PWM= )
Arduino TM
IOREF
ICSP
ICSP2
ON
POWER
01TX
0
RX0RESET
11
55
1010
1515
2020
2525
3030
A A
B B
C C
D D
E E
F F
G G
H H
I I
J J
13 12 11 ETH 9 8 7 6 5
SDCS
3 2 01TX RXAR
EF GND
5V A0
ANALOG IN
TX
RX
RESET
3V3
A1
A2
A3
A4
A5
VIN
GND
GND
DIGITAL (PWM SPI )
SCL SDA
<
IOREF
ICSP
CS
< <
Previous Circuit + Ethernet Shield38 / 44
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Additional SWChecklist:
mosquitto messagebroker
MQTTLens ChromeExt./App
pubsubclient lib@knolleary
ARE
FGND
RESE
T3V
3L
TXRX
USB
EXT
PWR
SEL
PWR
ICSP
TX RX
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9 8DIGITAL
7 6 5 4 3 2 1 0
1
5V GndPOWER
www.adruino.cc
ANALOG INVin 0 1 2 3 4 5
ADRUINO
Arduino - Sensor NodePublish data to the topic sensors/led/status every 2 seconds.
These values are the actual device state with considering localinput to the sensors (potentio and push button)
The data consist of a status (either "ON" or "OFF") and of anintensity (any integer ranging 0 - 254) in the following JSONformat:
{ "data": { "status": "ON", "intensity": 200 }}
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MQTTLens - Client NodeSubscribe to the topic sensors/led/status.
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Refs
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Refs1. Arduino - Official Site | Tutorials2. Guide - Getting Started | Windows3. Tutorials - WebClient | WebClientRepeating | EthernetBegin4. Playground - WebClient POST5. MQTT and CoAP, IoT Protocols6. A Brief, but Practical Introduction to the MQTT Protocol and its Application to
IoT | Zoetrope7. Earthshine Design, Arduino Starter Kit Manual: A Complete Beginners Guide to
the Arduino
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ENDEueung Mulyana
http://eueung.github.io/ET3010/arduinoET-3010 | Attribution-ShareAlike CC BY-SA
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