IoT (Internet of Things) Course
Just like computers or mobiles are connected through
internet, you can also connect your home appliances to
the internet and you can turn them on/off or monitor
them using an app on you mobile. This is called IoT (Inter-
net of Things).
Contents
1 - LEDs (Turning pins ON/OFF)
2 - Input Buttons
3 - Relays and Transistors
4 - NodeMCU with WiFi
5 - NodeMCU as Hot Spot
6 - App Development
7 - Control LEDs with App (WiFi)
8 - ThingSpeak Server
9 - Control LEDs with App (Internet)
10 - PWM (Analog Outputs)
11 - Aanalog Inputs
12 - Temperature Sensor
13 - Light Sensor
14 - Sound Sensor
15 - Flex Sensor
16 - Force Sensor
17 - Gas Sensor
18 - Soil Moisture Sensor
19 - Motion Sensor
20 - Distance Sensor
21 - Humidity Sensor
22 - IR Sensor
23 - Arduino IoT Cloud
Project 1 - Control Home Appliance with App
through Internet
Project 2 - Irrigation Monitoring System (Internet)
Project 3 - Water Level Monitoring System (Internet)
1 - LEDs (Light Emitting Diodes)
LEDs are small lights which can be used to
check if the pins are on or off
2 - Input Buttons
Input buttons are used to control different
functions of a circuit. For example volume but-
tons in a portable speaker, buttons to set date/-
time in a digital clock, there are many other uses
too.
3 - Relay and Transistor
Arduino pins have 5V only which cannot be
used to turn on/off AC, fan or a machine, thats
why we use relays which can be operated by
arduino and then relay can turn on/off different
appliances.
4 - NodeMCU with WiFi
You will learn how to connect nodeMCU
with your WiFi and turn on/off LEDs using IP
address and a browser.
5 - NodeMCU as Hot Spot
In this case nodeMCU becomes a WiFi
router itself with its own name and password.
Any phone or laptop can be connected to it and
different appliances can be controlled wireless-
ly
6 - App Development
In this section, you will learn how you can
create you own app using MIT App Inventor.
These apps can be used to control or monitor
different system over the internet.
7 - Control LEDs with App (WiFi)
We will create an app in this section which
will interact with nodeMCU through WiFi. You
can control different appliances wirelessly with
WiFi.
8 - ThingSpeak Server
A server is necessary for data transmission
over the internet. For example you send a mes-
sage to your friend on whatsapp, what if his
phone is off, where this message will go ? This
message will to the whatsapp server and will
wait there untill you friends phone is on again.
ThingSpeak server does the same for IoT
projects, you can monitor the data too.
9 - Control LEDs with App (Internet)
In this section you will learn how to control
different appliances or machines with an app
from anywhere in the world.
10 - PWM (Analog Outputs)
NodeMCU is a digital device which means
we can take only 0 or 3.3V at its output pins but
PWM (Pulse Width Modulation) is a process by
which we can take at the pin between 0 and
3.3V, for example 1V, 2V, 2.3V etc.
11 - Analog Inputs (Sensors)
PWM is used for analog outputs but what
about analog inputs?? NodeMCU has one pin,
A0, for analog inputs. This pin is very important
because most of the sensors will be used on
this pin.
12 - Temperature Sensor
This sensor is used to maintain temperature.
If temperature increases/decreases a fan,AC or a
heater gets turned on automatically and when
required temperature is achieved it is off auto-
matically.
13 - Light Sensor
This sensor is used to make a night switch
which can automate porch, lawn or street lights.
In the evening lights will be on and in the morn-
ing lights will be off automatically.
14 - Sound Sensor
This sensor will detect sound and take actions.
You clap, lights will be on, clap again, lights will
be off.
15 - Flex or Bend Sensor
This sensor is used to sense the amount of
bend in something, normally used in biotech
wearables like artificial limbs etc.
16 - Force Sensor
This sensor is normally used in digital bal-
ances or in robotics to detect that robot has
grabbed something. There are many other uses
too.
17 - Gas Sensor
This sensor is used to detect the gas leakage.
It can also measure the amount of concentra-
tion of the gas.
This sensor detects the moisture level in soil
and can automatically water the plants when
moisture level is low.
19 - Motion Sensor
This sensor detect motion, can be used in se-
curity systems or for automatic lights. Until
someone is present in the room or office, lights
will be on, when no one is present lights are off
automatically.
20 - Humidity Sensor
It detect humidity and temperature as well
and can turn on ac AC or fan if humidity or tem-
perature exceeds certain level
21 - IR Sensor
Infra Red sensors can be used in burglar
alarms or in counters to count products, persons
or vehicles.
22 - Arduino IoT Cloud
Arduino IoT Cloud is another IoT server like
thingSpeak. It is easy to use, has some advantag-
es some disadvantages but it is very useful in
some cases.
