Design of IoT Wireless Programmer for Microchip AVR Microcontrollers’ OTA Firmware Updates

Abstract Sensor Networks (WSN) are mainly composed of intelligent interconnected devices (things) that require remote ubiquitous over-the-air re-programming. Conse- quently, existing functionalities are updated, and firmware errors and security flaws are corrected along with the addition of new functionality. These enable their designated applications to be dynamically re-purposed. In this paper, a reliable design of an IoT Wireless Microchip ATMEL AVR Programmer device that provides firmware OTA updates utilizing Wi-Fi and LoRa technologies is proposed. It supports both the official Program and Debug Interface (PDI) and Tiny Programming Interface (TPI) for Microchip ATMEL AVR programming and debug- ging. TPI and PDI protocols are supported by the Microchip ATMEL AVR ATtiny and ATxmega family of microcontrollers. The research’s fundamental contribution is to realize wireless communication for the standard official Microchip ATMEL AVR Programmer for remotely writing, reading, erasing, and verifying a microcontroller’s Flash and EEPROM memories without the need for a custom bootloader. Simulations are performed utilizing the AVRDUDESS and the NetBurner Virtual COMM Port Converter applications that proved robust firmware OTA up- dating procedures. Experimental work is conducted on the AVR ATtiny10/20 and ATxmega32A4U microcontrollers, which proved an outstanding performance of sending a 6.315KB firmware file within 25 and 35 seconds using Wi-Fi and LoRa respectively.