Search icon CANCEL
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Internet of Things Programming with JavaScript
Internet of Things Programming with JavaScript

Internet of Things Programming with JavaScript: Get the best out of Arduino and Raspberry Pi Zero to develop Internet of Things projects using JavaScript

Arrow left icon
Profile Icon Ruben Oliva Ramos
Arrow right icon
€32.99
Paperback Feb 2017 298 pages 1st Edition
eBook
€17.99 €26.99
Paperback
€32.99
Subscription
Free Trial
Renews at €18.99p/m
Arrow left icon
Profile Icon Ruben Oliva Ramos
Arrow right icon
€32.99
Paperback Feb 2017 298 pages 1st Edition
eBook
€17.99 €26.99
Paperback
€32.99
Subscription
Free Trial
Renews at €18.99p/m
eBook
€17.99 €26.99
Paperback
€32.99
Subscription
Free Trial
Renews at €18.99p/m

What do you get with Print?

Product feature icon Instant access to your digital eBook copy whilst your Print order is Shipped
Product feature icon Paperback book shipped to your preferred address
Product feature icon Download this book in EPUB and PDF formats
Product feature icon Access this title in our online reader with advanced features
Product feature icon DRM FREE - Read whenever, wherever and however you want
Table of content icon View table of contents Preview book icon Preview Book

Internet of Things Programming with JavaScript

Chapter 2. Connecting Things to the Raspberry Pi Zero

You need to learn how to connect things to your Raspberry Pi Zero, and also looked at the architecture and differentiate between the pins we can use for the purpose we defined. This is the reason we have this section--to help you with the sensors we can connect and give the basics of how to connect other things to your device. In this section, we will explain how to configure the Raspberry Pi; now you cannot avoid learning how to connect to your Raspberry Pi sensors to read analog inputs connected to it.

We will cover the following topics to make our hardware communicate with the board:

  • Connecting digital inputs: Sensor DS18B20
  • Connecting analog inputs using an MCP3008 ADC converter
  • Connecting a real-time clock (RTC)

Connectting digital input - sensor DS18B20

The Raspberry Pi has digital pins, so in this section, we will look at how to connect a digital sensor to the board. We will use the digital sensor DS18B20, which has a digital output and can be perfectly connected to a digital input in our Raspberry Pi sensor. The main idea is to take temperature readings from the sensor and display them on the screen.

Hardware requirements

We will require the following hardware to take the temperature reading:

  • Temperature sensor DS18B20 (waterproof)
  • One resistor of 4.7 kilo-ohms
  • Some jumper wires
  • A breadboard

We will use a waterproof sensor DS18B20 and a 4.7 kilo-ohm resistor:

Hardware requirements

This is the waterproof sensor that we are using in this project.

Hardware connections

The following diagram shows the circuit on the breadboard, with the sensor and the resistor:

Hardware connections

In the following image, we can see the circuit with the sensor:

Hardware connections

Configuring the one-wire protocol

Open a terminal in the Raspberry Pi, and type the following:

sudo nano /boot/config.txt

You should type the following line at the bottom of the page to configure the protocol and define the pin where the one-wire protocol will communicate:

dtoverlay=w1-gpio

The next step is to reboot the Raspberry Pi. After a few minutes, open the terminal and type the following lines:

sudo modprobew1-gpio
sudo modprobe w1-therm

Enter the folder and select the device that will be configured:

cd /sys/bus/w1/devices
ls

Select the device that will be set up. Change  xxxx to the serial number of the device that will set up in the protocol:

cd 28-xxxx
cat w1_slave

You will see the following:

Configuring the one-wire protocol

After that, you will see one line which says Yes if it appears that the temperature reading is done like this: t=29.562.

Software configuration

Let's now look at the code to display the temperature in degrees Celsius and Fahrenheit every second on the screen.

Here we import the libraries...

Connecting analog inputs using an MCP3008 ADC Converter

If we want to connect analog sensors to the Raspberry Pi, we need to use an Analog-to-Digital Converter (ADC). The board doesn't have analog inputs; we use the MCP3008 to connect analog sensors. This is a 10-bit ADC and has eight channels. This means that you can connect up to eight sensors that can be read from the Raspberry Pi Zero. We don't need special components to connect them. They can be connected with SPI to the Raspberry Pi's GPIOs.

The first step is to enable SPI communication:

  1. Access the Raspberry Pi terminal and type the following command:
    sudo raspi-config
    
  2. Select Advanced Options, as shown in the following screenshot:
    Connecting analog inputs using an MCP3008 ADC Converter
  3. Enable SPI communication by selecting the SPI option:
    Connecting analog inputs using an MCP3008 ADC Converter
  4. Select <Yes> to enable the SPI interface:
    Connecting analog inputs using an MCP3008 ADC Converter
  5. The final screen looks like the following screenshot when we enable the SPI interface. Select <Ok>:
    Connecting analog inputs using an MCP3008 ADC Converter

Raspberry Pi GPIO header

The following screenshot is a chart of the GPIO pins of the Raspberry Pi Zero. In this case, we will use the SPI configuration interface (SPI_MOSI, SPI_MISO, SPI_CLK, SPI_CE0_N):

Raspberry Pi GPIO header

The following diagram shows the name of the pins of the MCP3008 chip that you connect to the Raspberry Pi: 

Raspberry Pi GPIO header

The following image shows the temperature sensor:

Raspberry Pi GPIO header

You need to connect the following pins according to the next description:

  • VDD to 3.3 volts
  • VREF to 3.3 volts from the Raspberry Pi Zero
  • Pin AGND to GND
  • Pin CLK (clock) to GPIO11 of the Raspberry Pi
  • DOUT to GPIO9
  • Pin DIN to GPIO10
  • Pin CS to GPIO8 and the pin
  • Pin the MCP3008D GND to Ground

This connection is represented in the following figure:

Raspberry Pi GPIO header

The following image shows the connections of the sensor to the ADC MCP3008 and the Raspberry Pi:

Raspberry Pi GPIO header

Reading the data with a Python script

In the next section, you will create the MCP3008.py file; you need to follow the next steps:

  1. Open the terminal on your Raspberry Pi Zero.
  2. Enter the interface in...

Connectting digital input - sensor DS18B20


The Raspberry Pi has digital pins, so in this section, we will look at how to connect a digital sensor to the board. We will use the digital sensor DS18B20, which has a digital output and can be perfectly connected to a digital input in our Raspberry Pi sensor. The main idea is to take temperature readings from the sensor and display them on the screen.

Hardware requirements

We will require the following hardware to take the temperature reading:

  • Temperature sensor DS18B20 (waterproof)

  • One resistor of 4.7 kilo-ohms

  • Some jumper wires

  • A breadboard

We will use a waterproof sensor DS18B20 and a 4.7 kilo-ohm resistor:

This is the waterproof sensor that we are using in this project.

Hardware connections

The following diagram shows the circuit on the breadboard, with the sensor and the resistor:

In the following image, we can see the circuit with the sensor:

Configuring the one-wire protocol


Open a terminal in the Raspberry Pi, and type the following:

sudo nano /boot/config.txt

You should type the following line at the bottom of the page to configure the protocol and define the pin where the one-wire protocol will communicate:

dtoverlay=w1-gpio

The next step is to reboot the Raspberry Pi. After a few minutes, open the terminal and type the following lines:

sudo modprobew1-gpio
sudo modprobe w1-therm

Enter the folder and select the device that will be configured:

cd /sys/bus/w1/devices
ls

Select the device that will be set up. Change  xxxx to the serial number of the device that will set up in the protocol:

cd 28-xxxx
cat w1_slave

You will see the following:

After that, you will see one line which says Yes if it appears that the temperature reading is done like this: t=29.562.

Software configuration

Let's now look at the code to display the temperature in degrees Celsius and Fahrenheit every second on the screen.

Here we import the libraries used...

Connecting analog inputs using an MCP3008 ADC Converter


If we want to connect analog sensors to the Raspberry Pi, we need to use an Analog-to-Digital Converter (ADC). The board doesn't have analog inputs; we use the MCP3008 to connect analog sensors. This is a 10-bit ADC and has eight channels. This means that you can connect up to eight sensors that can be read from the Raspberry Pi Zero. We don't need special components to connect them. They can be connected with SPI to the Raspberry Pi's GPIOs.

The first step is to enable SPI communication:

  1. Access the Raspberry Pi terminal and type the following command:

    sudo raspi-config
    
  2. Select Advanced Options, as shown in the following screenshot:

  3. Enable SPI communication by selecting the SPI option:

  4. Select <Yes> to enable the SPI interface:

  5. The final screen looks like the following screenshot when we enable the SPI interface. Select <Ok>:

Raspberry Pi GPIO header


The following screenshot is a chart of the GPIO pins of the Raspberry Pi Zero. In this case, we will use the SPI configuration interface (SPI_MOSI, SPI_MISO, SPI_CLK, SPI_CE0_N):

The following diagram shows the name of the pins of the MCP3008 chip that you connect to the Raspberry Pi: 

The following image shows the temperature sensor:

You need to connect the following pins according to the next description:

  • VDD to 3.3 volts

  • VREF to 3.3 volts from the Raspberry Pi Zero

  • Pin AGND to GND

  • Pin CLK (clock) to GPIO11 of the Raspberry Pi

  • DOUT to GPIO9

  • Pin DIN to GPIO10

  • Pin CS to GPIO8 and the pin

  • Pin the MCP3008D GND to Ground

This connection is represented in the following figure:

The following image shows the connections of the sensor to the ADC MCP3008 and the Raspberry Pi:

Reading the data with a Python script

In the next section, you will create the MCP3008.py file; you need to follow the next steps:

  1. Open the terminal on your Raspberry Pi Zero.

  2. Enter the interface in your Pi terminal...

Connecting an RTC


To control a system, it is very important to have a circuit that can read the time; it can help control the outputs from the Raspberry Pi or detect an action at a specific time. We will interface an RTC module DS3231 with the Raspberry Pi.

I2C setup

The first step is to enable the I2C interface by performing the following steps:

  1. Select Advanced Options:

  2. Enable the I2C option, as shown in the following screenshot:

  3. Select <Yes> on the next screen:

  4. Select <Ok>:

  5. Then select <Yes>:

  6. Next, select <OK>:

DS3231 module setup


The module DS3231 is a real-time clock. It can be used to get the time and date from an integrated circuit, so it can work with your system to control specific events that you want to program from an embedded chip. It can work perfectly with the Raspberry Pi Zero in order to get the time and date in real time.

You need to be sure that you have the latest updates. To do that, type the following commands in your terminal:

sudo apt-get update
sudo apt-get -y upgrade

Modify the system file with the following command:

sudo nano /etc/modules

Add the following lines to the modules.txt file:

snd-bcm2835 
i2c-bcm2835 
i2c-dev 
rtc-ds1307

Hardware setup

In this section, we will look at the pins of the RTC module:

DS3231   Pi GPIO 
GNDP     1-06 
VCC      (3.3V) 
SDA      (I2CSDA) 
SCL      (I2CSCL)

This is the RTC module, and we can see the pins of the chip:

The following diagram shows, the circuit connection:

The following image shows the final connection...

Left arrow icon Right arrow icon
Download code icon Download Code

Key benefits

  • • This is a practical guide to help you configure and build a complete distributed IoT system from scratch using JavaScript
  • • Utilize the power of Node and HTML5 to develop web services and a centralized web server, enabling high-level communication between connected devices
  • • Control all your connected devices from the browser by setting up a common dashboard

Description

The Internet of Things is taking the tech world by storm, and JavaScript is at its helm. This book will get you to grips with this exciting new technology. Where do Node.js, HTML5 and Windows 10 IoT Core come in with JavaScript and IoT? Why Raspberry Pi Zero rather than Arduino? How do you configure and build an IoT network from scratch? All your IoT JavaScript questions are answered in this book.

Who is this book for?

This book is for developers who are interested in learning how to communicate with connected devices in JavaScript to set up an IoT system. Some basic knowledge of JavaScript is expected. Hobbyists who want to explore the potential of IoT in JavaScript will also find this book useful.

What you will learn

  • With this book, you?ll learn about: ? Setting up a centralized web server to connect IoT devices ? Connecting sensors and actuators to devices ? Sending data to web server connected devices ? Understanding Internet of Things using web services and database ? Configuring dashboards using HTML5 and JavaScript ? Controlling and monitoring devices connected from dashboards ? Building apps for smartphones to control different devices
Estimated delivery fee Deliver to Finland

Premium delivery 7 - 10 business days

€17.95
(Includes tracking information)

Product Details

Country selected
Publication date, Length, Edition, Language, ISBN-13
Publication date : Feb 17, 2017
Length: 298 pages
Edition : 1st
Language : English
ISBN-13 : 9781785888564
Category :
Languages :
Tools :

What do you get with Print?

Product feature icon Instant access to your digital eBook copy whilst your Print order is Shipped
Product feature icon Paperback book shipped to your preferred address
Product feature icon Download this book in EPUB and PDF formats
Product feature icon Access this title in our online reader with advanced features
Product feature icon DRM FREE - Read whenever, wherever and however you want
Estimated delivery fee Deliver to Finland

Premium delivery 7 - 10 business days

€17.95
(Includes tracking information)

Product Details

Publication date : Feb 17, 2017
Length: 298 pages
Edition : 1st
Language : English
ISBN-13 : 9781785888564
Category :
Languages :
Tools :

Packt Subscriptions

See our plans and pricing
Modal Close icon
€18.99 billed monthly
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Simple pricing, no contract
€189.99 billed annually
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just €5 each
Feature tick icon Exclusive print discounts
€264.99 billed in 18 months
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just €5 each
Feature tick icon Exclusive print discounts

Frequently bought together


Stars icon
Total 95.97
Smart Internet of Things Projects
€32.99
Internet of Things Programming with JavaScript
€32.99
Practical Internet of Things with JavaScript
€29.99
Total 95.97 Stars icon

Table of Contents

9 Chapters
1. Getting Started with Raspberry Pi Zero Chevron down icon Chevron up icon
2. Connecting Things to the Raspberry Pi Zero Chevron down icon Chevron up icon
3. Connecting Sensors - Measure the Real Things Chevron down icon Chevron up icon
4. Control-Connected Devices Chevron down icon Chevron up icon
5. Adding a Webcam to Monitor Your Security System Chevron down icon Chevron up icon
6. Building a Web Monitor and Controlling Devices from a Dashboard Chevron down icon Chevron up icon
7. Building a Spy Police with the Internet of Things Dashboard Chevron down icon Chevron up icon
8. Monitoring and Controlling Your Devices from a Smart Phone Chevron down icon Chevron up icon
9. Putting It All Together Chevron down icon Chevron up icon
Get free access to Packt library with over 7500+ books and video courses for 7 days!
Start Free Trial

FAQs

What is the delivery time and cost of print book? Chevron down icon Chevron up icon

Shipping Details

USA:

'

Economy: Delivery to most addresses in the US within 10-15 business days

Premium: Trackable Delivery to most addresses in the US within 3-8 business days

UK:

Economy: Delivery to most addresses in the U.K. within 7-9 business days.
Shipments are not trackable

Premium: Trackable delivery to most addresses in the U.K. within 3-4 business days!
Add one extra business day for deliveries to Northern Ireland and Scottish Highlands and islands

EU:

Premium: Trackable delivery to most EU destinations within 4-9 business days.

Australia:

Economy: Can deliver to P. O. Boxes and private residences.
Trackable service with delivery to addresses in Australia only.
Delivery time ranges from 7-9 business days for VIC and 8-10 business days for Interstate metro
Delivery time is up to 15 business days for remote areas of WA, NT & QLD.

Premium: Delivery to addresses in Australia only
Trackable delivery to most P. O. Boxes and private residences in Australia within 4-5 days based on the distance to a destination following dispatch.

India:

Premium: Delivery to most Indian addresses within 5-6 business days

Rest of the World:

Premium: Countries in the American continent: Trackable delivery to most countries within 4-7 business days

Asia:

Premium: Delivery to most Asian addresses within 5-9 business days

Disclaimer:
All orders received before 5 PM U.K time would start printing from the next business day. So the estimated delivery times start from the next day as well. Orders received after 5 PM U.K time (in our internal systems) on a business day or anytime on the weekend will begin printing the second to next business day. For example, an order placed at 11 AM today will begin printing tomorrow, whereas an order placed at 9 PM tonight will begin printing the day after tomorrow.


Unfortunately, due to several restrictions, we are unable to ship to the following countries:

  1. Afghanistan
  2. American Samoa
  3. Belarus
  4. Brunei Darussalam
  5. Central African Republic
  6. The Democratic Republic of Congo
  7. Eritrea
  8. Guinea-bissau
  9. Iran
  10. Lebanon
  11. Libiya Arab Jamahriya
  12. Somalia
  13. Sudan
  14. Russian Federation
  15. Syrian Arab Republic
  16. Ukraine
  17. Venezuela
What is custom duty/charge? Chevron down icon Chevron up icon

Customs duty are charges levied on goods when they cross international borders. It is a tax that is imposed on imported goods. These duties are charged by special authorities and bodies created by local governments and are meant to protect local industries, economies, and businesses.

Do I have to pay customs charges for the print book order? Chevron down icon Chevron up icon

The orders shipped to the countries that are listed under EU27 will not bear custom charges. They are paid by Packt as part of the order.

List of EU27 countries: www.gov.uk/eu-eea:

A custom duty or localized taxes may be applicable on the shipment and would be charged by the recipient country outside of the EU27 which should be paid by the customer and these duties are not included in the shipping charges been charged on the order.

How do I know my custom duty charges? Chevron down icon Chevron up icon

The amount of duty payable varies greatly depending on the imported goods, the country of origin and several other factors like the total invoice amount or dimensions like weight, and other such criteria applicable in your country.

For example:

  • If you live in Mexico, and the declared value of your ordered items is over $ 50, for you to receive a package, you will have to pay additional import tax of 19% which will be $ 9.50 to the courier service.
  • Whereas if you live in Turkey, and the declared value of your ordered items is over € 22, for you to receive a package, you will have to pay additional import tax of 18% which will be € 3.96 to the courier service.
How can I cancel my order? Chevron down icon Chevron up icon

Cancellation Policy for Published Printed Books:

You can cancel any order within 1 hour of placing the order. Simply contact customercare@packt.com with your order details or payment transaction id. If your order has already started the shipment process, we will do our best to stop it. However, if it is already on the way to you then when you receive it, you can contact us at customercare@packt.com using the returns and refund process.

Please understand that Packt Publishing cannot provide refunds or cancel any order except for the cases described in our Return Policy (i.e. Packt Publishing agrees to replace your printed book because it arrives damaged or material defect in book), Packt Publishing will not accept returns.

What is your returns and refunds policy? Chevron down icon Chevron up icon

Return Policy:

We want you to be happy with your purchase from Packtpub.com. We will not hassle you with returning print books to us. If the print book you receive from us is incorrect, damaged, doesn't work or is unacceptably late, please contact Customer Relations Team on customercare@packt.com with the order number and issue details as explained below:

  1. If you ordered (eBook, Video or Print Book) incorrectly or accidentally, please contact Customer Relations Team on customercare@packt.com within one hour of placing the order and we will replace/refund you the item cost.
  2. Sadly, if your eBook or Video file is faulty or a fault occurs during the eBook or Video being made available to you, i.e. during download then you should contact Customer Relations Team within 14 days of purchase on customercare@packt.com who will be able to resolve this issue for you.
  3. You will have a choice of replacement or refund of the problem items.(damaged, defective or incorrect)
  4. Once Customer Care Team confirms that you will be refunded, you should receive the refund within 10 to 12 working days.
  5. If you are only requesting a refund of one book from a multiple order, then we will refund you the appropriate single item.
  6. Where the items were shipped under a free shipping offer, there will be no shipping costs to refund.

On the off chance your printed book arrives damaged, with book material defect, contact our Customer Relation Team on customercare@packt.com within 14 days of receipt of the book with appropriate evidence of damage and we will work with you to secure a replacement copy, if necessary. Please note that each printed book you order from us is individually made by Packt's professional book-printing partner which is on a print-on-demand basis.

What tax is charged? Chevron down icon Chevron up icon

Currently, no tax is charged on the purchase of any print book (subject to change based on the laws and regulations). A localized VAT fee is charged only to our European and UK customers on eBooks, Video and subscriptions that they buy. GST is charged to Indian customers for eBooks and video purchases.

What payment methods can I use? Chevron down icon Chevron up icon

You can pay with the following card types:

  1. Visa Debit
  2. Visa Credit
  3. MasterCard
  4. PayPal
What is the delivery time and cost of print books? Chevron down icon Chevron up icon

Shipping Details

USA:

'

Economy: Delivery to most addresses in the US within 10-15 business days

Premium: Trackable Delivery to most addresses in the US within 3-8 business days

UK:

Economy: Delivery to most addresses in the U.K. within 7-9 business days.
Shipments are not trackable

Premium: Trackable delivery to most addresses in the U.K. within 3-4 business days!
Add one extra business day for deliveries to Northern Ireland and Scottish Highlands and islands

EU:

Premium: Trackable delivery to most EU destinations within 4-9 business days.

Australia:

Economy: Can deliver to P. O. Boxes and private residences.
Trackable service with delivery to addresses in Australia only.
Delivery time ranges from 7-9 business days for VIC and 8-10 business days for Interstate metro
Delivery time is up to 15 business days for remote areas of WA, NT & QLD.

Premium: Delivery to addresses in Australia only
Trackable delivery to most P. O. Boxes and private residences in Australia within 4-5 days based on the distance to a destination following dispatch.

India:

Premium: Delivery to most Indian addresses within 5-6 business days

Rest of the World:

Premium: Countries in the American continent: Trackable delivery to most countries within 4-7 business days

Asia:

Premium: Delivery to most Asian addresses within 5-9 business days

Disclaimer:
All orders received before 5 PM U.K time would start printing from the next business day. So the estimated delivery times start from the next day as well. Orders received after 5 PM U.K time (in our internal systems) on a business day or anytime on the weekend will begin printing the second to next business day. For example, an order placed at 11 AM today will begin printing tomorrow, whereas an order placed at 9 PM tonight will begin printing the day after tomorrow.


Unfortunately, due to several restrictions, we are unable to ship to the following countries:

  1. Afghanistan
  2. American Samoa
  3. Belarus
  4. Brunei Darussalam
  5. Central African Republic
  6. The Democratic Republic of Congo
  7. Eritrea
  8. Guinea-bissau
  9. Iran
  10. Lebanon
  11. Libiya Arab Jamahriya
  12. Somalia
  13. Sudan
  14. Russian Federation
  15. Syrian Arab Republic
  16. Ukraine
  17. Venezuela