Design of a novel light-weight hardware module for wireless programming of resource-constrained embedded systems

Programmable embedded systems which are configured through a cable for operation, typically are inaccessible for reprogramming after deployment. Cheaper systems tend to be deployed in large numbers like Wireless Sensor Network (WSN) nodes forming a mesh network. In such cases, a reconfiguration or upgrade of firmware is difficult. A wireless channel for programming with broadcasting features addresses the problem. The design and implementation of add-on modules for Over The Air (OTA) programming of low-power resource-constrained embedded programmable devices is proposed. The design is based on an ATmega8 microcontroller (Atmel) based embedded circuit along with a TelosB node and can be easily extended to other systems. The programming procedure is implemented over an RF channel between the module attached to the programming terminal and the target devices to be programmed simultaneously - the key advantage with our design. IEEE 802.15.4 is used as the underlying protocol for our design making it platform independent. Link power characterization is done by performing Received Signal Strength Indication (RSSI) profiling at the receiver node. The applications of the protocol for a wireless mesh network are discussed and the effect of the programmer-target distance on the programming reliability is evaluated.