Selecting components is one of the most essential and critical processes when designing any electronic system. Poor component selection can lead to many problems within the design, PCB layout, power budget, etc. In this article, we will discuss how to select a component for a low-power-optimized design. Resistor The power dissipated by a resistor is…

The Internet of things (IoT), which includes the billions of devices now connected to the internet, has developed substantially over the past few years. IoT has become integral to several technologies and businesses. In fact, the number of active IoT devices has increased from 11.28 billion to 13.14 billion between 2021 and 2022. And the…

Transport Layer Security (TLS) is a security protocol which uses symmetric cryptography to secure data. In this tutorial, Client-Server communication will be setup using TLS Protocol so that data can be securely exchanged between them. The Mosquitto broker is used to provide TLS security. The Mosquitto broker uses 8883 port as an encrypted transmission port to securely exchange the data between clients. 

File Transfer Protocol (FTP) is a standard protocol for transferring files between a client and server over an internet network. The FTP protocol was written by Abhay Bhushan (IIT Kanpur) in 1971. In 1980, a TCP/IP version of the protocol as RFC 765 was introduced which became the de facto standard worldwide. in 1998, the protocol stack was updated for IPv6 support. Within this protocol, the security features were enabled by a  TLS/SSL layers called FTP Secure (FTPS). A new secured version of FTP is also widely used called SSH File transfer protocol (SFTP). The SFTP is quite different protocol than the traditional FTPS. 

In the previous tutorial, FTP protocol and file transfer over it between a Client and Server was discussed. The FTP protocol can really useful in many IoT applications. Many IOT devices are installed in places like nuclear plant, electrical grids and other industrial setups where these types of devices can get some bugs and need application software updates to fix them. On standard IoT protocols like MQTT, CoAP, etc, it is hard to update and reinstall application software because most of the IoT protocols are designed for IoT communication between devices and network but not for tasks like application updates.

In the previous tutorial, it was seen how FTP protocol can be used to update application software on an IoT device. However, FTP protocol has some security concerns as it is vulnerable to several kind of attacks like Brute force attack, FTP bounce attack, Packet capture, Port stealing (guessing the next open port and usurping a legitimate connection), Spoofing attack, Username enumeration etc. Therefore, secure variants of FTP protocols were developed. SSH File Transfer Protocol is one of the secure variants of the FTP protocol.   

Nowadays, most of the hotels and restaurants take online orders of food. Many hotels and restaurants either facilitate pre-ordering or even render delivery services in the local areas. In this project, an Hotel Order Management System is designed where a customer can pre-order food items using a mobile app and a Raspberry Pi based Server manages to cater menu items and book orders.

Emails are the most commonly used communication in the today’s digital era. The emails can also be way of communication with IoT devices. The emails can be used to pass commands to IoT devices. The devices can then be programmed and configured to read emails received and act accordingly. There can be interesting applications built this way. For receiving emails, the IoT devices need to configure as an Email Client. They can retrieve emails only over a standard email protocol. Internet Message Access Protocol (IMAP) is one of the standard email message protocols.  

ESP32 is a powerful 32-bit controller that clocks at speeds 160~240 MHz. Designed for IoT, the controller has on-chip Wi-Fi (40 MHz), Bluetooth 4.0, Bluetooth Low Energy, CAN, and an Ethernet interface. With 34 GPIO, 18 analog pins, 16 software PWM channels, 4 SPI ports, 2 I2C ports, 2 I2S ports, and 2 UART ports,…

Connecting embedded microcontrollers to the internet is a crucial task in modern applications. The embedded controllers, particularly in consumer devices and wearables, now essentially require ping online. This is more important as the devices are getting smarter. Connecting to the internet is not just crucial but a hefty task as well. The typical TCP/IP stack…

The communication technologies used by IoT devices to communicate data with each other are called IoT networks. Some the examples of IoT networks are cellular networks like LTE-M and NB-IoT, WiFi, Bluetooth Low Energy, Sigfox, LoraWAN, Zigbee, RFID, and Ethernet. IoT devices are usually connected via wireless communication technologies. In some rare cases, you may…

In the previous tutorial, it was mentioned that IMAP protocol is a standard email protocol which is used to store email messages and retrieve them. It was also mentioned that IMAP protocol can be used in IoT applications where commands can be passed to IoT devices by emails. This can be really helpful in certain situations like when security might be the main concern. Also, emails can be sent on any network without any special application or permissions. The IoT devices can receive emails as email clients where they can read emails and process information contained in them.

Application layer refers to OSI Level 5, 6 and 7. It is application layer in the TCP-IP model. In IOT architecture, this layer lies above the service discovery layer. It is highest layer in the architecture extending from the client ends. It is the interface between the end devices and the network. This layer is implemented through a dedicated application at the device end. Like for a computer, application layer is implemented by the browser. It is the browser which implements application layer protocols like HTTP, HTTPS, SMTP and FTP. Same way, there are application layer protocols specified in context to IOT as well.

IoT is the next development in modern life evolving through the present era of smartphones, tablets, and wearables. Connected cars, smart earphones, AI translators, personal assistance systems powered by augmented reality, vehicle tracking, AI-backed video surveillance, and many other embedded applications will become a part of our existence. These billions of “things” need internet connectivity…

In the previous tutorial, installation and configuration of RSMB Broker for MQTT-SN protocol implementation was discussed. In this tutorial, two devices will be setup to communicate over MQTT-SN protocol using RSMB Broker. One of these devices will be configured as MQTT-SN Client and other as the MQTT-SN Server.  The MQTT-SN needs a gateway when WSN (Wireless Sensor Network) devices want to send data to MQTT server which run on TCP/IP protocol or want to communicate with MQTT clients.

Device to Device Communication has a great role in IOT. In context to IOT systems, this device to device communication usually voids human interaction and control over the devices and the devices are meant to communicate with each other autonomously. In this tutorial, a similar demonstration of Device to Device Communication is presented.  

In the previous tutorials, the IOT devices designed were connecting with the internet network via Wi-Fi. Wi-Fi is a wireless standard. It is commonly used to provide data communication among mobile devices and the internet network. Another common standard used for networking devices and computers is Ethernet.   Ethernet is most commonly used Local Area Network (LAN) technology. It provides a wired communication to connect the devices to the Internet. 

In the previous tutorial, the Ethernet technology was used to connect an Arduino based IOT device with the internet network. The IOT devices can also be connected to internet network using mobile technologies like GSM, CDMA and GPRS. There are two major technologies for data transfers over cellular networks – GSM and GPRS. These two technologies differ from each other on the basis of data rates and the charges they take for their operation. 

SIM800 is a popular GSM GPRS modem. It supports General Packet Radio Service (GPRS) for connecting to the Internet. This module has built-in TCP/IP stack that can be accessed serially with AT commands.The modem needs to be configured by connecting it to a PC. In such setup, the SIM800 modem with SIM card acts as TCP client and the PC  acts as TCP server.  

In the previous tutorial, SIM800 module was configured as TCP-IP Client and a PC was configured as TCP-IP server. The two were setup to communicate over TCP-IP stack using an Arduino UNO as gateway. In this tutorial, the SIM800 will be configured as an MQTT Client and setup to communicate over MQTT protocol with a PC client. In the previous tutorial, the PC was configured as server to set SIM800 modem into working mode. In this project, the PC will serve as another client and communicate with the GSM GPRS modem via HiveMQ broker.