Automatic Street Light

This tutorial describes how we can transfer a simple light bulb into a light sensitive smart Light bulb

INFO

Programming Platform: Arduino IDE Type: Tutorial Difficulty: Intermediate Estimated Time: 2 hours

Components Required

Component	Quantity	Available in Kit
evive	1	evive
USB A-B Cable	1	evive
Photo-resistor	1	Starter Kit Home Automation Kit
10 kOhm Resistor	1	Starter Kit
5V Relay module	1	Home Automation Kit

Introduction:

A street light is a raised source of light on the edge of a road or path. Modern lamps may also light-sensitive that activate automatically when the light is or is not needed. Many street light systems are being connected underground instead of wiring from one utility post to another.

In this tutorial, we are going to make one light-sensitive bulb using LDR

LDR is a light dependent resistor which shows a drop in resistance proportional to applied light intensity.

Connections:

Warning: Working with LDR is not always reliable as it’s thershold depends on ambient lighting. You can use it outdoor but same system may not work with same threshold indoor

Threshold can be found on Serial monitor by uncommenting Serial.print(); instruction.

Procedure:

Connect Resistor and LDR in Series on evive’s mini breadboard
Provide supply to LDR and Resistor network
Take Analog input at A0
Connect Relay Module with Bulb
Connect Relay with evive
Check all connections.
Start Coding.

Coding Algorithm:

Start Serial to work at 9600 baud rate
Select Mode for input and Output operations.
Check state of LDR ( value between 0 to 1023)
If the value is more then threshold Turn OFF Light. ( as Light is More)
If the value is less then threshold Turn ON Light. ( as Light is less)
For Checking Threshold
- Uncomment serial.println(state);
- Upload Sketch
- Open Serial Monitor
- Place hand LDR and check value.
- Remove hand and check value
- Threshold = (dark value+ Light value) / 2
- Set threshold in the First line of code

CODE:

/* automatic Street light
 as a part of IoT kit
 made for evive

Made by Nihar Shah
 on 20 December 2017
*/
#define threshold 500 //thershold for switching
#define LDR_pin A0 //ldr input pin
#define light_relay 13 //light_relay shown in pin
int value;
void setup() {
 // put your setup code here, to run once:
 Serial.begin(9600);
 pinMode(LDR_pin, INPUT); // Select mode as analog input
 pinMode(light_relay, OUTPUT); // select mode as digital output
}

void loop() {
 value = analogRead(LDR_pin); // reading value
 // uncomment this for checking value ---&gt; 
 //Serial.println(value); 
 if (value &lt; thershold) //checking value
 {
 digitalWrite(light_relay, HIGH); // turning on
 }
 else
 {
 digitalWrite(light_relay, LOW); // turning off
 }
}

/* automatic Street light

as a part of IoT kit

made for evive

Made by Nihar Shah

on 20 December 2017

#define threshold 500 //thershold for switching

#define LDR_pin A0 //ldr input pin

#define light_relay 13 //light_relay shown in pin

int value;

void setup() {

// put your setup code here, to run once:

Serial.begin(9600);

pinMode(LDR_pin, INPUT); // Select mode as analog input

pinMode(light_relay, OUTPUT); // select mode as digital output

}

void loop() {

value = analogRead(LDR_pin); // reading value

// uncomment this for checking value --->

//Serial.println(value);

if (value < thershold) //checking value

{

digitalWrite(light_relay, HIGH); // turning on

}

else

{

digitalWrite(light_relay, LOW); // turning off

}