ThingSpeak accepts different data types and stores data in channels with 255 character fields. Channels represent data from devices. Write API keys send data to channels and read API keys read channel data. TaskTrackers send heartbeat messages to JobTrackers every few minutes to report status and available slots.

1. CAT III Answer Key
1. ThingSpeak accepts strings, integers, decimal degrees, and any encoded data. ThingSpeak
stores data as strings of up to 255 characters per field. ThingSpeak organizes data by
channels, where a channel represents data from a given device or process.
2. The write API key is used for sending data to the channel and the read API key(s) is used to read the
channel data. When we create a channel, by default, a write API key is generated. We generate read
API keys by clicking the ‘Generate New Read API Key’ button
3 The TaskTrackers in the Hadoop cluster send out the heatbeat messages to the JobTracker, usually
every few minutes to reassure the JobTracker that they are still alive.
These messages also inform the JobTracker of the number of available slots, so the JobTracker can
stay up to date with where in the cluster, new work can be delegated.
4 a. Secondary NameNode
b. NameNode
c.DataNode
d.TaskTracker
5 Tez
6 Storm topology is composed of Spouts and Bolts.
Spout is a source of streams (sequence of tuples), for example, sensor data stream.
The streams emitted by the Spouts are processed by the Bolts.
Bolts subscribe to spouts , consume the streams, process them and emit new streams.
7

2. Any one diagram
8 Latency
Virtualization Technology choice
Failures or churning
Network Management
Platform and Security
9 The Fog nodes perform computation and storage of the sensed data in the Rail Monitoring
System.
In the system, sensors sense and monitor the status of train systems to identify potential
hazardous spots earlier on and respond to diverse situations with flexibility. The sensors can use
wired or wireless interfaces to transmit data to the server.
10.

3. PART – B
11. The conventional methods which are in use today like SMS are costly. Since IOT is cost effective compared to
SMS, monitoring of energy usage at lower cost is made possible. Daily consumption reports are generated
which can be monitored by user through Android application and/or web portal. The system is more reliable
and accurate reading values are collected from energy using devices. Live readings of devices can be viewed
using Android application. Also, the readings can be viewed online. The human interference is avoided and
all the values are kept maintained in the central server. The communication medium is secure and tampering
of energy meters or theft of electricity can be identified easily. If an error occurs in the system, the value in
the central server will not be updated. Since the values are stored in the central database, the reports are
made accessible from anywhere in the world. Also, the server is online 24x 7
Or

4. #include "ThingSpeak.h"
#include <ESP8266WiFi.h>
#include <LiquidCrystal_I2C.h>
#include <Wire.h>
#include <Adafruit_INA219.h>
Adafruit_INA219 ina219;
LiquidCrystal_I2C lcd(0x27, 16, 2);
uint32_t currentFrequency;
int int_busvoltage = 0;
int x, y, z;
float busvoltage = 0;
float current_mA = 0;
float power_mW = 0;
unsigned long previousMillis_V = 0;
unsigned long previousMillis_I = 0;
unsigned long previousMillis_P = 0;
const int Field_number_1 = 1;
const int Field_number_2 = 2;
const int Field_number_3 = 3;
bool measure_V = true;
bool measure_I = false;
bool measure_P = false;
//------- WI-FI details ----------//
char ssid[] = "XXXXXXXXXX"; //SSID here
char pass[] = "YYYYYYYYY"; // Password here
//--------------------------------//
//----------- Channel details ----------------//
unsigned long Channel_ID =123456; // Your Channel ID
const char * WriteAPIKey = "ABC123CDEF456"; //Your write API key
//-------------------------------------------//
WiFiClient client;
void setup()
{
lcd.init();
lcd.backlight();
lcd.setCursor(0, 0);
lcd.print("IoT Based Energy");
lcd.setCursor(0, 1);
lcd.print("Monitoring Systm");
delay(2000);
if (! ina219.begin())
{

5. lcd.clear();
lcd.setCursor(0, 0);
lcd.print("FAILED TO FIND");
lcd.setCursor(0, 1);
lcd.print("INA219 MODULE");
while (1)
{
delay(10);
}
}
Serial.begin(115200);
WiFi.mode(WIFI_STA);
ThingSpeak.begin(client);
}
void loop()
{
internet();
measure();
upload();
}
void internet()
{
if (WiFi.status() != WL_CONNECTED)
{
while (WiFi.status() != WL_CONNECTED)
{
WiFi.begin(ssid, pass);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("CONNECTING TO");
lcd.setCursor(0, 1);
lcd.print("Wi-Fi NETWORK...");
delay(5000);
}
}
}
void measure()
{
busvoltage = ina219.getBusVoltage_V();
int_busvoltage = busvoltage * 1000;
current_mA = ina219.getCurrent_mA();
power_mW = ina219.getPower_mW();
lcd.clear();

6. lcd.setCursor(0, 1);
lcd.print("V:");
lcd.print(busvoltage);
lcd.setCursor(9, 1);
lcd.print("mA:");
(current_mA < 3) ? (lcd.print("000")) : (current_mA < 10 && current_mA
> 3) ? (lcd.print("00"), lcd.print((int)current_mA)) : (current_mA < 100
&& current_mA >= 10) ?
(lcd.print('0'), lcd.print((int)current_mA)) :
(lcd.print((int)current_mA));
lcd.setCursor(0, 0);
lcd.print("POWER(mW):");
lcd.print((int)power_mW);
delay(2000);
}
void upload()
{
unsigned long currentMillis_V = millis();
if (currentMillis_V - previousMillis_V >= 15000 && measure_V == true)
{
previousMillis_V = currentMillis_V;
x = ThingSpeak.writeField(Channel_ID, Field_number_1, busvoltage,
WriteAPIKey);
if (x == 200)
{
measure_V = false;
measure_I = true;
}
}
unsigned long currentMillis_I = millis();
if (currentMillis_I - previousMillis_I >= 15000 && measure_I == true)
{
previousMillis_I = currentMillis_I;
y = ThingSpeak.writeField(Channel_ID, Field_number_2, current_mA ,
WriteAPIKey);
if (y == 200)
{
measure_I = false;
measure_P = true;
}
}
unsigned long currentMillis_P = millis();
if (currentMillis_P - previousMillis_P >= 15000 && measure_P == true)

7. {
previousMillis_P = currentMillis_P;
z = ThingSpeak.writeField(Channel_ID, Field_number_3, power_mW,
WriteAPIKey);
if (z == 200)
{
measure_P = false;
measure_V = true;
}
}
}
12.

10. 13.

12. 14.
Any one related diagram and its explanation.