An Introduction to the Internet of Things
Figure 1
Computers connected to form a network
Figure 2
When two networks are connected they form an
internet. These networks can connect to the worldwide internet known as
The Internet.
Figure 3
The original and most basic Arduino - the
Arduino Uno
Figure 4
A WiFi shield for the Arduino Uno
Figure 5
An ESP32 WROOM 32
The Arduino IDE
Figure 1
Arduino Splash Window
Figure 2
Arduino IDE
Figure 3
Preferences Window
Figure 4
Enter additional boards manager URLs
Figure 5
Boards Manager
Figure 6
Select esp32 and Install
Figure 7
USB connectors
Figure 8
Click the
compile and run
buttonFigure 9
Code compiled and uploaded
Figure 10
Serial Monitor
Understanding the code
Connecting the first sensor
Figure 1
Temperature Sensor module (DHT22)
Figure 2
Wiring the DHT11 Temperature Sensor when it is
not part of a module
Figure 3
Library Manager
Connecting the second sensor
Figure 1
Light Level with a Light Dependent Resistor
(LDR)
Combining the two circuits
Figure 1
Circuit with the DHT22 temperature sensor and
and LDR light for measuring light intensity
Using MQTT for the Internet of Things
Figure 1
MQTT Architecture
Figure 2
Installing the PubSubClient library for MQTT
messaging
Figure 3
An MQTT broker on the Internet
Figure 4
An MQTT broker on a private network
Subscribing to an MQTT topic
Figure 1
Running MQTTX
Figure 2
New connection in MQTTX
Figure 3
MQTTX connected to broker
Figure 4
New Subscription
Figure 5
Subscribed