In the buildings with different scale and complexity, automation system is becoming more and more common, and its importance is also increasing. Convenience, safety and energy efficiency are key factors to promote intelligent monitoring and control of residential and building products. From lighting to window louver control, to complex heating, ventilation and air conditioning (HVAC) components, and meter metering / management systems, residential and commercial buildings are equipped with more intelligent automation solutions. Every year, this trend urges manufacturers around the world to release thousands of products in this market.

A typical building automation system consists of three components: sensors, a communication channel and actuators.

Interoperability between building automation system and KNX software on ultra-low power MCU

A group of sensors collects and processes the data in the environment. According to the sensing information, a message is transmitted to different parts of the network operated by the actuator through the communication channel.

Take the security system composed of smoke detector, intrusion sensor and alarm as an example. As long as smoke is detected or someone intrudes into the house illegally, the alarm receives a message and makes a loud sound. The basic requirement is that the alarm can "understand" the smoke and the messages sent by the intrusion detector. You can imagine what happens if manufacturer a's smoke detector uses communication protocol a, while manufacturer B's intrusion detector uses communication protocol B? How can the alarm understand the messages from these two detectors? In addition, what if there are hundreds of manufacturers who use proprietary communication protocols? It is clear that there must be a common "language" among all automation components to achieve their interoperability. And that's what KNX software does. KNX protocol can realize interoperability of building automation devices without considering manufacturers, product lines or even core functions. With the help of KNX, communication between all interconnected devices is possible. For example, a light switch can communicate not only with a light bulb, but also with smoke detectors, window shutter controls, and any other networking device.

In this type of communication, data security and reliability are very important. The msp430fr5969 microcontroller with non-volatile fram technology embedded in the chip can realize the following functions:

Replay (replay) attacks are prevented by using a non-volatile sequential counter that increments when each data frame is received.

The manufacturer sets the secure storage of the key (fdsk) and all the security keys established during configuration using the memory protection unit (PMU).

Encryption of KNX network traffic with hardware AES accelerator.

The fast write to non-volatile memory after receiving each data frame reduces the risk of packet loss.

It detects the low-energy storage of key data when the power is cut off, and saves the current state of the device.

Take thermostat, for example, where fram technology has a huge impact. Even the most basic thermostat on the market can let users create different temperature system configurations to achieve the purpose of energy saving. By continuously recording the user settings and the latest system status in non-volatile memory, MSP430? Microcontroller supporting embedded fram technology can effectively resume normal operation after power failure, so as to realize a low energy consumption system and ensure the comfort of the user's environment.