Page 406 - ARM Based Microcontroller Projects Using MBED

392 16. INTERNET OF THINGS (IOT)

then send the collected data to a cloud so that users can access the system from anywhere on
Earth and at any time. The users can also access the system locally through the common
processor.

16.3 PROJECT 1—HOME IoT PROJECT

16.3.1 Description
This is a simple home IoT project. In this project three Nucleo-F411RE-type development
boards are connected to three Bluetooth modules. One of the development boards (node:
IoTTemperature) measures the ambient temperature in the living room through a tempera-
ture sensor chip. The second development board (node: IoTLight) measures the light level in
children’s room and sends messages ON or OFF to informs the user about the light state. The
third development board (called node: IoTWindow) is connected to a switch in the kitchen
window and it checks whether or not the window is open and it sends messages OPEN or
CLOSED to inform the user about the window state. A PC receives information from all three
development boards through Bluetooth and displays this information on the screen every 5s.

16.3.2 Aim

The aim of this project is to show how a simple IoT project can be developed using Nucleo-
F411RE development boards and Bluetooth modules.

16.3.3 Block Diagram

The block diagram of the project is shown Fig. 16.4. The project consists of three develop-
ment boards, three Bluetooth modules, a temperature sensor chip, a light dependent resistor
(LDR), and a switch.

FIG. 16.4 Block diagram of the project.