The Covid-19 pandemic and the ensuing race to develop a vaccine to combat it have highlighted the importance of the cold chain – the supply chain for materials that could be compromised or damaged irreparably if the temperature at which they are stored are not kept within very narrow limits. Many pharmaceutical, chemical, and food products fall into this category. Some vaccines, for example, are very sensitive to temperature changes and require storage at very low temperatures that must be meticulously maintained, from the point of production to the point of distribution. To ensure that the cold chain is maintained uninterrupted, a tracking system is needed that is as comprehensive, automated and error-free as possible. Asset Tracking Asset Tracking The task of tracking products or materials along each stage of the path that divides them from the place of production to the end user so that, at any time, it is possible to determine where the asset is. The simplest way to trace is to apply a barcode with a unique identifier for each asset. The code can then be scanned with a barcode reader or recorded each time it is moved from one point to another along the chain. Asset Tracking With Barcode Scanner Today, all these steps and movements can be recorded in a central tracking database for further analysis and query. The development of electronic technology has led to the introduction of innovative low-power electronic devices for tracking assets, such as temperature, humidity, shock/vibration and pollutant sensors, as well as GPS locators. Also very important in this area are data loggers, devices capable of recording and saving information from sensors related to the tracking process. Most data loggers used in asset tracking applications have low power consumption and can therefore be battery operated. The chart on the left shows some classic asset tracking apps that use data loggers. These devices include a sensor to obtain the data to be recorded, a processor, non-volatile memory for data storage, and a real-time clock. Some typical asset tracking applications that include data loggers are common in cold chain tracking systems, because they avoid having to resort to frequent communications (usually over the Internet or mobile network) with the central system. Cold Chain Asset Tracking Application Temperature monitoring and recording are not only necessary to ensure product safety, but are also a requirement by the Federal Drug Administration (FDA) for quality control of food, drug, and cosmetic products. Therefore, it is necessary to use a low-power battery-powered device capable of obtaining and storing the temperature at regular intervals. In addition to the data logger, we will also need a low-power microcontroller (MCU), the true brain of the tracking system, capable of implementing software control algorithms and interacting with sensors, monitors, and serial or USB communication channels. One example of an MCU capable of meeting these requirements is the ML630Q466/Q464 from Lapis Technology (belonging to the Rohm family), a 32-bit low-power MCU based on an ARM Cortex-M0+ core with two different ROM sizes (128) KB/ 64 KB) and is capable of supporting USB interface. These MCUs feature various serial ports for connecting multiple sensors and recording their output. They have built-in LCD drivers, RC-ADC for accurate temperature measurement, a full-speed USB 2.0 controller, and support for multiple clock modes. This level of integration eliminates the need for many external components, allowing for a more compact design. As shown in the diagram below, the MCU can be battery operated thanks to its low power consumption, it can manage multiple external sensors, a display, a USB communication channel, and a wireless communication module (optional). There is a wide range of sensors capable of covering cold chain tracing application requirements. These sensors include accelerometers, optical sensors (ambient light, RGB), MEMS-based pressure sensors, and magnetic sensors (Hall ICs and magnetometers). Accelerometers such as the KXTJ3-1057 can be used for motion alert detection, angle detection, shock/free fall detection, activity, click sensing, engine health, and machine health. 32-bit low power MCU suitable for application For optical sensors, ambient light sensors are great for monitoring the light intensity in an environment or for controlling the backlight of a data logger. RGB color sensors detect color changes in an object, sort products, and products matching a specific color. In addition, barometric pressure sensors can help detect changes in altitude, inland navigation, weather stations, and pressure changes. Finally, Hall Integrated Circuits are ideal for door detection, alarm detection, contactless switches, and forward/backward position, while magnetometers are great for location/position detection and as an electronic compass for trackers. In addition to a USB connection, the addition of a module capable of supporting wireless connectivity is a great opportunity, paving the way for a possible integration of the tracking system with the Internet of Things framework. In the connected Internet of Things space, sensor nodes provide the capabilities needed for asset tracking data loggers. Sharing data with other nearby assets and other parts of the surroundings allows the asset tracker to get the most comprehensive picture possible of the environments the asset is in. Wireless modules include standard protocols such as Bluetooth (especially low energy), Wi-Fi, and other more specialized IoT protocols. This article was originally published on the sister site EE Times. .