Hardware Requirements

Popular Single-Board Computers on the Market

Table 1-2 lists some of the most popular SBCs on the market, per https://en.wikipedia.org/wiki/Comparison_of_single-board_computers#Operating_system.

Table 1-2

Popular Single-Board Computers

Name	PCIe	USB[2]			Storage			Networking		Communication			Generic I/O
		2	3	Device	On-board	Flash slots	SATA	Eth.	Wi-Fi	Bt.	I2C	SPI	GPIO	Analog
Raspberry PiZero W	No	No	No	OTG	No	microSD	No	No	b/g/n	4.1 + BLE	Yes	Yes	17	No
Raspberry PiZero	No	No	No	OTG	No	microSD	No	No	No	No	Yes	Yes	17	No
Raspberry Pi Model B+	No	4	No	No	No	microSD	No	10/100	No	No	Yes	Yes	17	No
Raspberry Pi Model B	No	2	No	No	No	SD	No	10/100	No	No	Yes	Yes	8	No
Raspberry Pi Model A	No	1	No	No	No	SD	No	No	No	No	Yes	Yes	8	No
Raspberry Pi 3 Model B	No	4	No	No	No	microSD	No	10/100	b/g/n	4.1	Yes	Yes	17	No
Raspberry Pi 2 Model B	No	4	No	No	No	microSD	No	10/100	No	No	Yes	Yes	17	No
Intel Galileo Gen 2[46]	1 mini	1	No	Yes	8 MB Flash + 8 KB EEPROM	SD	No	10/100	No	No	Yes	Yes	20	12-bit ADC, 6 PWM
Banana Pi M3[137]	No	2	No	OTG	8GB eMMC	microSD	USB to SATA 2.0 adapter	GbE	a/b/g/n	4	Yes	Yes	40	12-Bit-ADC (CON1 for Touch)
Banana Pi M2	No	2	No	OTG	No	microSD	No	GbE	a/b/g/n	No	Yes	Yes	40	12-Bit-ADC (CON1 for Touch)
Banana Pi[11]	No	2	No	OTG	No	SD	SATA 2.0	GbE	No	No	Yes	Yes	26	12-Bit-ADC (CON1 for Touch)

As of this writing, the most popular SBCs today are the Raspberry Pi and Banana Pi. They are equally popular with hobbyists and serious users. While Raspberry Pi runs OSes like Noobs, Raspbian, and Windows IoT, Banana Pi run Linux and Android 4.x. Raspberry Pi developed from Model Zero to the current one, which is 3 Model B+ and, as you can see from Table 1-2, there have been huge hardware improvements. Raspberry Pi 3 B+ how has an ARM Cortex-A53 1.4GHz CPU, which is an improvement over the Raspberry Pi 3 B, which had an ARM Cortex-A53 1.2GHz CPU. The RAM size has not changed; however, there is an enhancement in Wi-Fi, which now has the capability of up 5GHz transfers. The Ethernet support has been increased from 100Mbps to 300Mbps. The use of Banana Pi is preferred by users who have projects that are closely linked with mobile applications since the operating system is Android which, although built on Linux, has Android as the kernel for its operations. For the projects in this book I have chosen Raspberry Pi. The operating system we are going to use is Raspbian, which is an adaptation of the Debian OS. We are not using Noobs because we want to make commercial-grade applications on the SBC and we are not using Windows IoT since we need an OS that has a desktop and development IDE embedded in it. So the choice of Raspbian is pretty obvious.

Use Table 1-3 to help you decide which Raspberry Pi to use for your projects.

Table 1-3

Raspberry Pi Technical Specifications

Raspberry Pi Platform	RAM	Processor	USB	Ethernet	Wi-Fi	Bluetooth	HDMI	Other Video	MicroSD
Raspberry Pi A+	512MB	700 MHz ARM11	1 port	-	-	-	Yes	DSI, Composite	Yes
Raspberry Pi B+	512MB	700 MHz ARM11	4 ports	10/100Mbps	-	-	Yes	DSI, Composite	Yes
Raspberry Pi 2 B	1GB	900 MHz Quad-Core ARM Cortex-A7	4 ports	10/100Mbps	-	-	Yes	DSI, Composite	Yes
Raspberry Pi 3 B	1GB	1.2 GHz, Quad-Core 64-bit ARM Cortex A53	4 ports	10/100Mbps	802.11n	4.1	Yes	DSI, Composite	Yes
Raspberry Pi 3 B+	1GB	1.4 GHz 64-bit ARM Cortex A53	4 ports	300/Mbps/PoE	802.11ac	4.2	Yes	DSI, Composite	Yes
Raspberry Pi Zero	512MB	1 GHz single-core ARM11	1 micro USB	-	-	-	Mini-HDMI	-	Yes
Raspberry Pi Zero Wireless	512MB	1 GHz single-core ARM11	1 micro USB	-	802.11n	4.1	Mini-HDMI	-	Yes

Before we move on to the topic of microcontrollers in the next section, let’s look at a very important aspect of the Raspberry Pi architecture, which is the overlay of GPIO pins on the SBC board. These pins are used for communication with auxiliary hardware such as sensors or other microcontrollers that can do serial communication such as Arduino. Figure 1-1 shows the GPIO overlay of Raspberry Pi 3 Model B+.

In Figure 1-1, you can see that there are a total 40 GPIO pins. They have a structure and it is important that you understand it in order to use it. The pins are numbered from 1 to 40 in the diagram. Pin 1 and 17 are for supplying power output to your device (3.5 volts). Pins 2 and 4 are used for giving a power output of 5 volts each. Pins numbered 6, 9, 14, 20, 25, 30, 34 and 39 are used for grounding the circuit. The rest of the pins are used for GPIO. You will be using this information later when you create a complete circuit for some IoT-based solutions.

Let’s now discuss microcontrollers and how they are used.

Single-Board Microcontrollers

SBMs are microcontrollers built into a single circuit board; they are used in industrial and commercial applications to interface between industrial and commercial devices such as ones that use serial bus communication. They are used in applications to develop solutions requiring interfacing with industrial machines or network interfaces such as ones requiring Modbus communication protocol.

Arduino is a very popular single-board microcontroller and is used by hobbyists and students to learn hardware implementations and how to control and build hobby machines that interface with common C and C++ programs. However, we are going to use Arduino for an industrial-grade purpose. Let’s compare three models from the Arduino line in order to select the best microcontroller for our purpose.

Arduino Uno, Arduino Mega, and Arduino Mega 2560 are the three models we are going to use for our comparison. All three single-board microcontrollers use a 16MHz frequency processor. The printed circuit board dimensions of the Mega and Mega 2560 are higher than the Arduino Uno, which is smaller than both of them by half in length at 2.7 inches x 2.1 inches to 4 inches x 2.1 inches. The Arduino Mega 2560 has the highest flash memory of 256kb, whereas Arduino Uno has the lowest flash memory of 32kb. Arduino Mega has 128kb. Flash memory is very important as far as SBMs are concerned because whatever programs you write for controlling the hardware through your application has to be written to the flash memory first. If the flash memory is low, you cannot write an industrial-grade application on top of it. Both the Mega models have higher EEPROM and SRAM than the Arduino Uno; also, the Mega models have 54 GPIO pins while the Uno has just 14 pins. Why do we need more pins for our applications? We will be using our applications for communicating with serial Modbus communication interfaces which may need two or three devices connected at the same time. If the number of pins is less, we will be limited in having parallel devices. So we need higher pins for this purpose.

So the best model for us is the Arduino Mega 2560, which has the highest flash memory.

Arduino Mega 2560

Figure 1-2 shows the GPIO overlay of the Arduino Mega 2560 and its communication architecture.

You can see the area marked as GPIO pins in the single-board computer diagram in Figure 1-2. This model supports both digital pins and analog pins. Digital pins are used to control and communicate with devices such as digital sensors, and analog pins are used to communicate with analog devices such as analog sensors. This model has a USB interface, which is used for serial bus communication with another device such as a SBC like the Raspberry Pi. You will look at this in detail later in the part of the book on how to connect and communicate between the Raspberry Pi and Arduino. Figure 1-3 shows the overlay of GPIO pins on the Arduino Mega 2560 board.

As you can see in the figure, the pin numbers starting from D mean digital pins; these are the slots where you will connect digital sensors and devices. The pins starting from A are analog pins and can be used to communicate with analog devices. For now, this is what you need to understand. You will look at all of this in detail once you start to assemble your system.

IoT sensors

IoT is an extension of internet connectivity to everyday physical devices and objects. When devices like sensors and internet connectivity are added to it and embedded to physical devices like art objects or any other object that display information on creation date, an artist description of the object, recently modified date, etc., then the IoT is formed. We now have the concept of automatic reordering cabinets which can order food online as they gets empty upon consumption. By embedding IoT sensors in everyday objects we are making them smart and accessible for human betterment.

You can see from Table 1-4 that there are a variety of sensors available and they range from digital to analog to measure and detect objects using Wi-Fi cameras to detecting a change in weight or load on an electronic device. The uses and applications of these sensors are limitless and can give fresh life to an IoT application. You will be using these common types of sensors in this book and I will outline them in more detail as you build your solutions.

Drones

A drone is defined by Wikipedia (https://simple.wikipedia.org/wiki/Unmanned_aerial_vehicle) as an unmanned aerial vehicle operated through remote control devices. Drones usually have a small microcontroller embedded inside them which has the capability to detect changes in air pressure, the proximity of objects, acceleration, etc. It has many IoT sensors embedded within it, making it smarter than manned planes. However, there are very few automatic drones that do not require human supervision to fly and work. Most drones have human supervisors who control their activities through a remote control mechanism.

You will be using an industrial grade drone in the solution for the telecom domain case study. You will need an industrial grade drone that can take payloads up to 3.5 pounds or 1.5 kgs and has a range of 5 km since you will be flying it for detection purposes around an area in a particular locality. The minimum flight time you need is 30 minutes because this is the minimum time required to gather some decent data to apply machine learning. These types of drones are definitely not cheap; they start at $2,500.

Modbus Device

You will be using another device in the energy segment of the case study. A Modbus device is a standard communication protocol for connecting to industrial devices, such as machines to a computer. They are also used to gather and send data. There is a master device or microcontroller that uses the Modbus protocol to communicate with its slaves, which can be up to 247 in number. This makes the protocol very robust, which is the reason I chose an Arduino Mega 2560 single-board microcontroller (because it has a lot of space for analog and digital pins on its board for communication).

In the industrial world, three-phase Modbus energy meters are used, but this is difficult to replicate in a normal environment, so I recommend using a single-phase energy meter instead, which uses the Modbus RTU communication protocol. There are plenty of options available from companies such as Schneider Electric and others.

Required Software

For running the exercise in this book, you will need Python 3.x installed. I recommend you use the default Python installation that comes with the Raspbian OS for this purpose. Python is a simple distribution and it does not require any installation whatsoever, unlike Anaconda. All the coding exercises in this book work on this version of Python. The exercises and solutions in this book do not support Windows nor have they been tested on any version of Windows. Using the Raspbian OS is a must to make them work. Please follow the steps for installation that are given in the installation section of this book.

You will also be using the Arduino IDE to communicate between the Arduino and Raspberry Pi, so the Arduino is going to work as a slave to the Raspberry Pi in your solutions. This can be installed via the apt-get command, which you will see later in the installation part of the book.

Summary

This chapter covered SBCs and how they have developed historically. You learned about the most popular SBCs in the market, such as Banana Pi, Raspberry Pi, and Arduino. In an in-depth comparison, you explored the features of popular SBCs in terms of USB, storage, networking, and communication features. You also learned about the Raspberry Pi and more specifically the Raspberry Pi 3 Model B+ that you will be using to use as a master node in your IoT and IIoT projects later in this book. You learned about the GPIO pins located on the Raspberry Pi and their uses. You also learned about the single-board microcontrollers and how they are different from the single-board computers. You also learned that the single-board microcontrollers in IoT and IIoT applications are generally used as slaves to the single-board computers like Raspberry Pi. You also saw that the most popular single-board microcontroller is the Arduino and you looked at a table about the types of SBMs and feature information like processors, I/O modules, frequency, voltage, etc.

You then looked at the Arduino Mega 2560 and its layout and learned about its GPIO pins. Then you learned about the most important topic of the book: IoT sensors and their types and applications. You also learned about drones, as they will be used to collect data for the telecom application in this book. You learned about a Modbus device and how it is used to build a commercial application. Lastly, you got a list of software that will be used through this book.