Upgrade System Of LoRa Wireless Device Software Based On Bluetooth

With the continuous development of the Internet of Things technology,the application range of various mainstream wireless technologies is becoming wider and wider.Among them,LoRa wireless technology shines in the field of wireless meter reading.With the continuous popularity and application of wireless meter reading technology,its problems is emerging gradually.In the application scenarios of wireless valve and wireless water meter,wireless devices are usually installed in pipeline wells or basements.If the equipment is upgraded and maintained by conventional wired methods,it will be difficult for the maintenance personnel to do it due to the poor installation environment.And if the devices are upgraded by wired means when they have been running,there will be some damages to the device,some of which are recoverable,such as tearing off the surface film.And some are also unrecoverable,such as the damage to waterproof performance caused by disassembling equipment.Therefore,it is necessary to perform firmware upgrades on LoRa wireless devices by wireless means.Furthermore,with the popularity of smart phones,it will be very convenient to design an Android APP of Android phones to upgrade the firmware of LoRa wireless devices on the device site.This paper proposes a wireless firmware upgrade scheme of LoRa device based on Bluetooth.And a hardware device is designed to communicate the Bluetooth module with the LoRa wireless transparent transmission module through the serial port,so that the user can communicate with LoRa wireless devices indirectly by the way of Bluetooth.Aiming at the security and reliability design of the entire wireless transmission system,an upper layer communication protocol is developed to further ensure the entire wireless transmission process,ensuring data transmission to the LoRa wireless device rightly.Moreover.this paper has made some provisions in the communication protocol layer for resume transmission.With some flags stored in the LoRa wireless device,the transfer next time can also resume from the breakpoint after the transmission process has a problem with the guarantee of the transmission protocol.For the firmware upgrade of the LoRa wireless device,the way of IAP is selected to do it.The BootLoader program is designed to send and receive data from the serial port,perform packet parsing and data verification according to the designed upper layer communication protocol.decrypt data using the AESI28-CBC algorithm,write data to Flash,and boot the device program to the new user program.The user program is also designed.In addition to the user function,it can receive commands from the serial port,wake up the device,and boot the program to the BootLoader.For the PC software,this paper designs an Android APP,which implements the functions of searching for Bluetooth,connecting Bluetooth devices,and getting Bluetooth services,and implements the designed upper layer communication protocol and AES128-CBC encryption algorithm.The firmware file data will be sent to LoRa wireless devices after being divided into packets and being encrypted.After experimental testing,the system can implement safe and reliable firmware upgrade function for LoRa wireless devices.