Development of an Electronic Device for Monitoring the Physical Parameters of Specialized Cargoes During Their Transportation

Specialized cargoes require compliance with special storage and transportation conditions, which necessitates the use of special electronic devices placed with the cargo. These monitoring devices measure the physical parameters critical for the cargo, carry out logging, and also record events when the parameters exceed the permissible limits. In this paper, the development of a device for controlling temperature, relative humidity and shock loads, suitable for use in the transportation of specialized goods is considered. The basis of the device is a microcontroller that supports Bluetooth Low Energy technology at the software and hardware levels. Temperature, humidity and acceleration sensors with a digital interface are used to measure environmental parameters. The event log is saved to a removable memory card. The design and algorithm of the device provides protection against falsification of recorded data, including the presence of a sensor for opening the case. The microcontroller’s software is based on the FreeRTOS real-time operating system. The dependence of the current consumed by the device on time has a pulse character, while the pulse amplitude reaches hundreds of milliamperes, in the interval between pulses the current is hundreds of microamperes, and the duration of this interval can be units–tens of seconds. The expected battery life of the device in monitoring mode is more than 40 days.