IoT
Cricket
Khairul Alam – making the Internet of Things accessible for everyone
Part 1: IoT made easy for everyone
T
he IoT (Internet of Things)
connects our physical and digital worlds together. It transforms our lives as we adapt and become more efficient by using data collected from our environment. For example, as we analyse temperature, light and sunshine over time, we may be able to work out how to reduce energy usage. This is just one example of how IoT is playing an important role in transforming our lives. IoT connects various types of devices to the Internet and allows them to interact with each other. The ‘Thing’ in the IoT can be any device with any kind of built-insensor that has the ability to collect and transfer data over a network without any human interaction. Common sensor types measure temperature and humidity, light, pressure, proximity, linear and angular position (accelerometers and gyroscopes), noise and air quality; RFID (radio-frequency identification) devices can also be.
How IoT works An IoT system normally comprises the following four fundamental components. (Fig.1 shows the IoT components and the interconnection among them.)
1. Device In an IoT system, a ‘device’ is an end node. A system developer will probably spend a big portion of their time creating this stage. A typical IoT device contains one or more sensors and a processing unit. Usually, microcontrollers are used for collecting and processing sensor data and sending it to the Cloud. Up to now, to make a such device you might have required specialised programming and electronics knowledge. However, this is changing rapidly and later in this article I will introduce an IoT module that enables you to make your own IoT device without advanced programming and electronics knowledge. Md. Khairul Alam is an Assistant Professor at the University of Asia Pacific, Dhaka, Bangladesh. He is an independent Cricket developer and does not work for Things On Edge.
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Fig.1. Main components of an IoT system [image credit: Rohm Semiconductor].
2. Connectivity At the heart of IoT is ‘connectivity’, which is vital for all IoT devices. To enable remote monitoring and control an IoT device must connect to a server, and IoT designs are mostly based on a client-server model. In a typical client-server system, a server provides resources to one or more clients. The server can be a web server or mail server, and client examples include a smartphone, laptop or tablet. One server can provide resources to multiple clients simultaneously. In a dedicated IoT system, an IoT device and mobile apps act like a client and the server can be a Cloud or local server. It has been observed that many developers, especially hobbyists, do not want to use the Cloud. They prefer to set up their own servers and services within their own local network to save time, avoid subscription fees and to enhance privacy. Whether connecting to a local or Cloudbased server, you need to adopt a wired or wireless connection medium like Ethernet, Wi-Fi, GPRS, Bluetooth or LoRa. Each of these has advantages and trade-offs in terms of range, bandwidth and power consumption, so choosing the right one for your device is very important. Many developers prefer Wi-Fi because it is already widely adopted and almost everyone has Wi-Fi at home. There is no need for an extra device such as a proprietary IoT hub, which would introduce an extra layer of complexity translating proprietary RF signals to Wi-Fi; and also the extra cost,
around £50 ($65). Wi-Fi also has greater bandwidth compared to other options. However, there is a big downside to Wi-Fi, which has greatly reduced its adoption in the IoT space – power consumption. Power requirements do not make Wi-Fibased IoT impossible, it’s just that not many companies have set themselves the challenge of addressing this issue. A few companies have started innovating in this space; Ring and Sonoff devices are good examples. Another company – Things On Edge – is one step ahead in this field. Although they don’t make a full IoT device, they have developed a compact Wi-Fi module to enable other makers to build their own Wi-Fi-connected IoT devices with excellent power efficiency. We will return to their product a little later in this article.
3. Data processing in the server Once the data is collected and stored, the server software may need to perform some
Fig.2. The all-important ESP8266 chip. Practical Electronics | June | 2021
