selected input/output - sensors and actuators

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Sensors & Actuators

Selected I/OsEueung Mulyanahttps://eueung.github.io/012017/inoutCodeLabs | Attribution-ShareAlike CC BY-SA

Outline

Preparation

Light/Laser Sensor

PIR Sensor

LM35 & DHT11

Processing & Local Visualization

Ultrasonic Sensor

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Preparation

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Preparation Notes

We reuse the previous nRF24L01+ example (Simple Remote Control) with some changes i.e.:for simplicity both nodes are now Nano-based, an LCD is attached to Node-2 for a better

communication and debugging experience.

In the next examples, the switch will be replaced with laser and PIRsensors.

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I2C LCD1602An LCD display that can display a max

of 16x2 characters.

As the pin resources of ucontroller is limited, your project maybe not able to use normal LCD shield after connected with acertain quantity of sensors/actuators i.e. if you are doing morethan a simple project, you may be out of pins using a normalLCD shield. With this I2C interface LCD module, you only need 2lines (I2C) to display information.

Interface: connect the I2C LCD1602 to the I2C port of Arduino(SDA - A4 and SCL - A5) and power this module with 5V.

Ref: arduino-info, elecrow

Node-1 & Node-2 (Both with nRF24L01+)6 / 74

Node-1 (Remote Switch / Sensor Node)7 / 74

Node-2 (Display Node)8 / 74

Node-19 / 74

Node-210 / 74

Install I2C LiquidCrystal Library11 / 74

#include <SPI.h> #include "nRF24L01.h"#include "RF24.h"

RF24 myRadio (7, 8);

const int SW1 = 5;const int SW2 = 6;

byte addresses[][6] = {"1Node"}; int dataTransmitted;

int button1;int button2;

void setup() { pinMode(SW1, INPUT); pinMode(SW2, INPUT); button1 = 0; button2 = 1; dataTransmitted = 10;

Serial.begin(115200); delay(1000);

myRadio.begin(); myRadio.setRetries(0,15); myRadio.setChannel(108); myRadio.setPALevel(RF24_PA_MAX);

myRadio.openWritingPipe( addresses[0]); delay(1000);}

void loop() { int newButton = digitalRead(SW1); if (newButton != button1) { button1 = newButton;

if (button1 == HIGH){ dataTransmitted = 20; } 12 / 74

Node-1

#include <SPI.h> #include "nRF24L01.h"#include "RF24.h"

RF24 myRadio (7, 8);

byte addresses[][6] = {"1Node"}; int dataReceived;

const int LED = 2;

#include <Wire.h>#include <LiquidCrystal_PCF8574.h>

LiquidCrystal_PCF8574 lcd(0x27);

int lcdexist;unsigned long started_waiting_at = 0;bool bklight = false;

void setup() { pinMode(LED, OUTPUT);

Serial.begin(115200); delay(1000);

myRadio.begin(); myRadio.setAutoAck(1); myRadio.setChannel(108); myRadio.setPALevel(RF24_PA_MAX);

myRadio.openReadingPipe(1, addresses[0]); myRadio.startListening();

Wire.begin(); Wire.beginTransmission(0x27); lcdexist = Wire.endTransmission();

lcd.begin(16, 2);}

void loop() { 13 / 74

Node-2

Switch ON14 / 74

Switch OFF15 / 74

Light/Laser Sensor

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Laser Mini Transmitter & Receiver Module17 / 74

Light/Laser Receiver ModuleUtilizing LDR and Voltage Comparator for Digital Output

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LDRLDR or Light Dependent Resistor (sometimes calleda photoresistor or photocell) is a two-terminal,resistive component that increases or decreases itsresistance depending on the light it senses. An LDRinitially has a very high resistance. But, as light fallson it, the resistance will drop, allowing more currentthrough.

Ref: Earthshine Design

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LDR Sensor ModuleLDR sensor module is used to detect the intensity oflight. It might have both analog output pin anddigital output pin labelled as AO and DOrespectively on the board. When there is light, theresistance of LDR will become low according to theintensity of light. The greater the intensity of light,the lower the resistance of LDR. The sensor has apotentiometer knob that can be adjusted to changethe sensitivity of LDR towards light.

Ref: LDR Sensor Module

Switch Replacement with a Laser Receiver21 / 74

Switch Replacement with a Laser Receiver22 / 74

PIR Sensor

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PIR SensorA PIR (Passive Infra-Red) sensor is an electronicsensor that measures infrared light radiating fromobjects in its �eld of view. Normally this type ofsensor would be used as a motion or proximitysensor. Quite often they are referred to as: PIR,Motion, Proximity, or Pyroelectric sensor.

The sensor in the PIR detects or "reads" infrared radiation "emitted"from objects all around us. Each object with a temperature aboveabsolute zero will radiate infrared, even us humans, and even though wemere humans cannot see this. Note that the PIR just uses a relativelysimple sensor - it is most de�nitely not an IR camera!

Ref: Testing and Playing with PIR sensors @Tweaking4All

Switch Replacement with a PIR Sensor25 / 74

LM35 & DHT11

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LM35 & DHT1127 / 74

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LM35LM35 is a linear temperature sensor with the outputvoltage calibrated in centigrade celsius. 1 degreecelsius makes an output voltage of 10mV. So whenyou have room temperature at 22C the LM35 givesyou a voltage of 220mV = 0.22V.

The sensor has only 3 pins: VCC which can be between +4V and +20V,GND and Vout. Vout has to be connected to one of the analog inputs andthat's all - in most cases.

Ref: connecting an arduino with a LM35 temperature sensor @heliosoph

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DHT11DHT11 is a temperature and humidity sensor with acalibrated digital signal output.

The DHT11 sensor has four pins. Connect the �rst pin on left of sensor('VCC') to 5V of your board, the second pin ('Data') to a digital pin andthe fourth pin ('GND') to ground. When the connecting cable is shorterthan 20m, a 5K pull-up resistor between the second Pin of sensor and 5Vis recommended.

Ref: DHT11 Temperature and Humidity Sensor Example @arduino.org

Install Library for DHTxx Sensors30 / 74

float tlm35;

void setup() { Serial.begin(9600);

//analogReference(INTERNAL);}

void loop() { tlm35 = 0.0; for(int j = 0; j < 10; j++) { tlm35 += analogRead(A0); delay(20); } tlm35 = tlm35 * 5.0 * 10.0 / 1023.0;

//tlm35 = tlm35 * 1.1 * 10.0 / 1023.0;

Serial.println(tlm35);}

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LM35

#include "DHT.h"

#define DHTPIN 3 #define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);

void setup() { Serial.begin(9600);

dht.begin();}

void loop() { delay(2000);

// Reading temperature or humidity takes about 250 milliseconds! // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor) float h = dht.readHumidity(); float t = dht.readTemperature();

if (isnan(h) || isnan(t)) { Serial.println("Failed to read from DHT sensor!"); return; }

Serial.println(t);}

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DHT11

Local Visualization & UI

Processing

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ProcessingProcessing is a �exible software sketchbook and alanguage for learning how to code within thecontext of the visual arts.

Since 2001, Processing has promoted software literacy within the visualarts and visual literacy within technology. There are tens of thousands ofstudents, artists, designers, researchers, and hobbyists who useProcessing for learning and prototyping.

Ref: Processing.org

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Processing is an open source language/development tool for writing programs in othercomputers. Useful when you want those othercomputers to talk with an Arduino, for instance todisplay or save some data collected by the Arduino.

How to Work with Processing?Write Arduino sketch as usual, except for input/output intended tobe retrieved from or sent to ProcessingWrite Processing program that receives/sends data from/toArduino

If you just want to control an Arduino board from a Processing program,you may want to use the Arduino Library for Processing.

Ref: Arduino Playground - Processing

Switch ExampleRef: Electronics @Processing.org 36 / 74

int switchPin = 5;

void setup() { pinMode(switchPin, INPUT); Serial.begin(9600); delay(1000);}

void loop() { if (digitalRead(switchPin) == HIGH) { //Serial.println(1); Serial.write(1); } else { //Serial.println(0); Serial.write(0); } delay(100); }

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Arduino

import processing.serial.*;

Serial port; int val; String stext;

void setup() { size(200, 200); frameRate(10); port = new Serial(this, "/dev/ttyUSB0", 9600);}

void draw() { if (0 < port.available()) { val = port.read(); } background(255); if (val == 0) { fill(0); stext = "OFF"; } else { fill(255,0,0); stext = "ON"; } rect(50, 50, 100, 100);

textAlign(CENTER); textSize(30); fill(255); text(stext, 100, 112);}

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Processing

Using Arduino IDE Serial Plotter39 / 74

Using Arduino IDE Serial Plotter40 / 74

Controlling a ServoRef: Electronics @Processing.org 41 / 74

Micro ServoTower Pro SG90 42 / 74

#include <Servo.h>

Servo myservo; int servoPin = 4; int val = 0;

void setup() { myservo.attach(servoPin); Serial.begin(9600); }

void loop() { if (Serial.available()) { val = Serial.read(); } myservo.write(val); delay(15); }

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Arduino

import processing.serial.*;

Serial port; float mx = 0.0;

void setup() { size(200, 200); noStroke(); frameRate(10); port = new Serial(this, "/dev/ttyUSB0", 9600);}

void draw() { background(0); fill(204); rect(40, height/2-15, 120, 25);

float dif = mouseX - mx; if (abs(dif) > 1.0) { mx += dif/4.0; } mx = constrain(mx, 50, 149);

noStroke(); fill(255); rect(50, (height/2)-5, 100, 5); fill(204, 102, 0);

rect(mx-2, height/2-5, 4, 5); int angle = int(map(mx, 50, 149, 0, 180)); port.write(angle); }

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Processing

Arduino Built-In Example - Graph45 / 74

void setup() { Serial.begin(9600);}

void loop() { Serial.println(analogRead(A0));

// wait a bit for the analog-to-digital converter // to stabilize after the last reading: delay(2);}

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Arduino

import processing.serial.*;

Serial myPort; // The serial portint xPos = 1; // horizontal position of the graphfloat inByte = 0;

void setup () { size(400, 300); myPort = new Serial(this, "/dev/ttyUSB0", 9600);

myPort.bufferUntil('\n'); background(0);}

void draw () { stroke(127, 34, 255); line(xPos, height, xPos, height - inByte);

if (xPos >= width) { xPos = 0; background(0); } else { xPos++; }}

void serialEvent (Serial myPort) { String inString = myPort.readStringUntil('\n');

if (inString != null) { inString = trim(inString); inByte = float(inString); println(inByte);

inByte = map(inByte, 0, 1023, 0, height); //inByte = map(inByte, 0, 100, 0, height); }}

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Processing

Circuit & Processing Plot48 / 74

HC-SR04

Ultrasonic Sensor

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Ultrasonic SensorHC-SR04 ultrasonic ranging sensor provides 2cm to400cm of non-contact measurement functionalitywith a ranging accuracy that can reach up to 3mm. Itis a very a�ordable proximity/distance sensor thathas been used mainly for object avoidance invarious robotics projects.

Each HC-SR04 module includes an ultrasonic transmitter, a receiver anda control circuit. It has 4 pins: VCC, GND, Trigger and Echo pin.

Install Arduino NewPing Library51 / 74

Install Processing gra�ca Library52 / 74

NewPing Example53 / 74

#include <NewPing.h>

#define TRIGGER_PIN 3 #define ECHO_PIN 4 #define MAX_DISTANCE 300

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);

void setup() { Serial.begin(9600); }

void loop() { delay(500); Serial.println(sonar.ping_cm()); }

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Arduino

import grafica.*;import processing.serial.*;

GPlot plot;

int i = 0; int points = 100; public float[] values;

Serial myPort; float inByte = 0;

void setup(){ size (900,450);

myPort = new Serial(this, "/dev/ttyUSB0", 9600);

GPointsArray points1 = new GPointsArray(points);

values = new float[points]; for (i = 0; i < points; i++) { points1.add(i,0); values[i]=0; }

plot = new GPlot(this); plot.setPos(25, 20); plot.setDim(750, 310);

plot.setXLim(0, points); plot.setYLim(0, 310);

plot.setTitleText("Distance"); plot.getXAxis().setAxisLabelText("Sample Time"); plot.getYAxis().setAxisLabelText("cm");

plot.setPoints(points1); }

void draw() { background(150);

GPointsArray points1 = new GPointsArray(points);

for (i = 0; i < values.length; i++) { 55 / 74

Processing

Processing Plot with gra�ca Library56 / 74

#include <NewPing.h>#include <Servo.h>

#define TRIGGER_PIN 3 #define ECHO_PIN 4 #define MAX_DISTANCE 300

Servo myservo; int servoPin = 5; int val = 0;

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);

void setup() { myservo.attach(servoPin); Serial.begin(9600); }

void loop() { val = analogRead(A0); val = map(val, 0, 1023, 0, 180); myservo.write(val); //delay(15);

delay(500); Serial.println(sonar.ping_cm()); }

Rotating SR04 with a Servo - Manually via a Potentiometer 57 / 74

Arduino

#include <NewPing.h>#include <Servo.h>

#define TRIGGER_PIN 3 #define ECHO_PIN 4 #define MAX_DISTANCE 300

Servo myservo; int servoPin = 5; int val = 0; int lastval = 0; unsigned long timer;

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);

void setup() { myservo.attach(servoPin); Serial.begin(9600); timer = millis();}

void loop() { val = analogRead(A0); val = map(val, 0, 1023, 0, 180);

int dif = val - lastval;

if(abs(dif)>1) { val = lastval + dif/4; } myservo.write(val); lastval = val; delay(15);

if((millis()-timer)>500) { Serial.println(sonar.ping_cm()); timer = millis(); }}

Rotating SR04 with a Servo - Try this too! 58 / 74

Arduino

HC-SR04 + SG9059 / 74

SR04 SonarOur previous case can be rearranged to make a simple DIY Sonar

(SOund Navigation And Ranging) system.

The following example was modi�ed from Dejan Nedelkovski's code.

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#include <NewPing.h>#include <Servo.h>

#define TRIGGER_PIN 3 #define ECHO_PIN 4 #define MAX_DISTANCE 300

Servo myservo; int servoPin = 5;

const int angle_start = 5; const int angle_end = 175; const int delaytime = 20;

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);

void setup() { myservo.attach(servoPin); Serial.begin(9600);}

void loop() { for(int i=angle_start;i<=angle_end;i++){ myservo.write(i); delay(delaytime);

Serial.print(i); Serial.print(","); Serial.print(sonar.ping_cm()); Serial.print("."); }

for(int i=angle_end;i>angle_start;i--){ myservo.write(i); delay(delaytime);

Serial.print(i); Serial.print(","); Serial.print(sonar.ping_cm()); Serial.print("."); }}

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Arduino

String distance="";String data="";String noObject;

float pixsDistance;int iAngle, iDistance;int index1=0;int index2=0;

final float MAX_DIST = 300; //-------------------------------------------------void setup() { size(1200, 700); smooth();

myPort = new Serial(this, "/dev/ttyUSB0", 9600); myPort.bufferUntil('.'); orcFont = loadFont("OCRAExtended-30.vlw");}//-------------------------------------------------void draw() { float covered_height = height*0.935; noStroke(); fill(0,4); rect(0, 0, width, covered_height);

fill(98,245,31); textFont(orcFont);

drawRadar(); drawLine(); drawObject(); drawText();}//-------------------------------------------------void serialEvent (Serial myPort) { data = myPort.readStringUntil('.');

data = data.substring(0,data.length()-1);

index1 = data.indexOf(","); angle= data.substring(0, index1); distance= data.substring(index1+1, data.length());

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Processing

Tools | Create Font64 / 74

Tools | Create Font65 / 74

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drawRadar()

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drawText()

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drawRadar()drawText()

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drawLine()

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drawObject()

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Refs/Resources

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Refs/Resources1. LDR Sensor Module Interface With Arduino2. Using a Photocell @Adafruit3. Photoresistor @ElectroSchematics4. Testing and Playing with PIR sensors @Tweaking4All5. Arduino Playground - Processing6. Processing Foundation7. Electronics - Processing.org8. Typography, Strings and Drawing Text9. Arduino library for DHT11DHT22, etc Temp & Humidity Sensors

10. A simple and con�gurable plotting library for Processing11. Clipart - Strain Gauge

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ENDEueung Mulyanahttps://eueung.github.io/012017/inoutCodeLabs | Attribution-ShareAlike CC BY-SA