Microcontroller based remote updating system using voice channel of cellular network

This paper presents a scheme of remote updating based on any existing cellular network. The scheme is successfully implemented on 8 bit general purpose microcontroller for quick prototyping and incorporating the remote update feature even for small applications in a cost effective manner. Existing cellular network is used to avoid the cost and hassles of creating and maintaining a dedicated network infrastructure. The updating system consists of two units. One is the central controlling unit located at a central place and the other is a remote standalone unit that is to be updated through this controlling unit as and when required. Both the units are provided with commercially available low-cost cellphones for establishing the communication during the update process. The remote unit consists of an additional updating microcontroller along with the main microcontroller. This updating microcontroller receives the code from the central unit through the cellphone attached to it and updates the main microcontroller of the remote unit. Two case studies for application of the remote updating scheme are presented in this paper. In one example, the program memory, i.e. the firmware, is updated, while in the other application, the nonvolatile EEPROM memory is updated in the main microcontroller of the remote unit through this remote updating scheme.