Internet of Things

The Internet of Things (IoT) is about interconnecting embedded systems. It brings together two evolving technologies: wireless connectivity and smart sensors. Combined with recent advances in low power microcontrollers, these new "things" are being connected to the internet easily and inexpensively, ushering in a second industrial revolution.

The most important criteria used when selecting the type of connectivity for an IoT node is that the value of the data collected must be worth the current draw, and often the biggest current draw in an IoT node is the radio. In other words, it's not necessary to use a 43Msps wireless connection if the system only needs to transmit 32 bytes of sensor data every two minutes.

A number of protocols are available for networking distributed embedded systems:

• WiFi: Draws the most power. Used for high data rate, high amounts of data. Useful for streaming applications such as security cameras, as well as systems where WiFi is already used and so can be easily connected.

» View Components for WiFi Connectivity

• Bluetooth: useful for low power, short distance networks.

» View Components for Bluetooth Connectivity

• 802.15.4: Used for low data rate, battery powered networks distributed over a wide area. Supports star networks, as well as peer-to-peer networking where each node can act as a repeater, retransmitting data received from other nodes thereby extending the range of the system.

» View Components for 802.15.4 Connectivity

Data is collected in an IoT node from different sensors. The type and accuracy of the sensor is dependent upon the value of the data being collected and the amount of data to be processed.

Learn more about the IoT Sensor Node
Block Diagram

Many IoT systems have some type of environmental sensors to measure motion, position, acceleration, pressure, temperature, humidity, etc. Optical sensors can detect the presence of light in different wavelengths, including infrared. Video camera sensors including CCD and CMOS light sensors are used where video monitoring is required such as automated highway traffic management systems. Some systems being monitored may already provide a signal and that can be fed to an analog to digital converter (ADC) or an analog front end.

Smart Sensors are sensors that have some data processing on board. These can be anywhere from environmental sensors that perform basic processing of the data, to high accuracy MEMS sensors with a gyroscope and accelerometer with integrated digital processing for sensor fusion calculations..

» View Smart Sensor Components

» View RFID/NFC Components

» View Optical Sensors

» View Video Sensors Link

» View Environmental and Motion Sensor Components

Typically the Internet of Things is about high integration in low power systems. Since the value of the data collected must be worth the current draw of the system, the choice of microcontroller is important not just for the processing power but also for the level of on-chip integration. As the level of integration has increased for microcontrollers, the power consumption has dropped, helping to enable the Internet of Things at just the right time.

Although an 8-bit microcontroller may be useful for simple, low data low bandwidth nodes, the majority of IoT applications with use either 16-bit or 32-bit microcontrollers. 16-bits are used for basic nodes of low to medium complexity where the data is not part of a realtime system. The advantage of 16 bits is that it can be the best compromise of low power and data throughput. However, the most common data bus for an IoT node is 32-bits where performance is essential and a high level of integration is required. Some 32-bit microcontrollers even have sensor interfaces and on-chip RF radios, perfect for IoT nodes.

Crucial to modern IoT nodes is the need for security. Most 32-bit processors introduced today now have some form of encryption, the most common being AES256. This increased security helps the processor perform a secure boot, insuring that the core is running the software is meant to run. Encryption security is also used to encrypt the data transmitted over the network, insuring that it is viewed only by those systems authorized to receive the data.

» View Microcontrollers for IoT

A voltage regulator is usually either on the board or integrated into the microcontroller to supply regulated current to the system. More sophisticated nodes with high frequency processors may have a power management chip, while low power battery-powered nodes may require a DC/DC converter or a battery management chip to supervise rechargeable batteries.

» View Low Dropout Regulators for IoT

» View DC/DC Converters for IoT

» View Power Management Components for IoT (link:

» View Battery Management Components

All the data collected needs to be stored somewhere. Many simple IoT nodes will use the memory available on the microcontroller, but more complex nodes may require additional Flash memory, either mounted on the circuit board or by a memory module inserted into an expansion slot. More sophisticated systems that might be found in a factory can require significant resources and can have additional RAM on the board. And last, there is The Cloud where the data can be uploaded, stored, and even processed then fed back to the IoT system.

While many IoT nodes can use the Flash memory on the node's microcontroller, some systems require additional memory for either the system program or for data storage. These systems can utilize Flash memory on the PC board (PCB).

» View Flash Memory Components

Although many IoT nodes will have enough RAM on the microcontroller to perform its work, some very high performance systems may require additional RAM memory. This may be for normal program storage, or for very high performance digital processing nodes the RAM may be loaded with the program memory on boot, enabling the system to run code out of RAM much faster than from Flash by reducing the wait states for the processor.

» View RAM Memory Components

Some IoT nodes may require the use of removable memory for expansion, security, or program memory storage.

» View Memory Module Components

Most IoT systems will transfer data to Cloud storage from the main host system. However, some IoT nodes may directly upload to cloud storage, or even get its code from cloud storage.

» View Cloud Storage Kits