In this paper, we propose a kind of novel energy-efficient programming approach for microcontroller units which helps to minimize processing power costs of any self-sustainable sensor device. This approach is based on an event driven programming principle taking advantage of flag-based logic. The framework called Entity Dust Container (EDC) was introduced for this purpose. Significant power savings can be achieved by application of EDC because it effectively emphasizes power-saving-modes of the device/sensor/… control unit. Especially implementation of such an approach in the frame of WSN (Wireless Sensor Network) management could prolong the working period of such network significantly. An efficiency of proposed framework was implemented and practically evaluated at experimental energy-harvesting wireless sensor node.