Introduction

Batteryless sensors can operate relying only on harvested ambient energy. Due to energy constraints, they operate intermittently and they are not always available for communication, prejudging the success of packet delivery among these devices. The patented solution provides a mechanism that measure the energy level of any batteryless IoT device and share this information over the network.

Technical features

The solution (TRL 6-7) is a PnP digital circuit that can automatically measure the energy level of any batteryless IoT device, without impacting the batteryless device’s energy budget. The circuit autonomously encodes the measured energy level over the backscatter channel, where the energy status of the node is shared over the network. The circuit works without microcontroller intervention and encodes the energy level by turning a fixed frequency, low-cost, ultra-low-power oscillator on for a specific time. Thus, it generates a burst with a different duration (i.e., number of pulses) related to the energy status. The circuit also decodes any received burst without microcontroller activity and provides the received energy via GPIO pins. On top of the proposed circuit, a protocol, namely TRAP grants that the node’s control system can use the information of the neighboring energy status to guarantee secure data communication. Indeed, the information carried by the energy status burst also includes the identification of the energy status sender node. The protocol has also been tested several times outside the lab, while the associated HW has only been realised in the lab; the inventors are devising prototypes and circuit boards to be used as demos, even outside an experimental context.

Possible Applications

• Batteryless sensor networks (WSN);
• Industrial Internet of Things, Asset tracking, Predictive maintenance, Automation;
• Smart traffic assistant, Smart cities, Remote controls;
• Smart home, Home appliances, Wearable electronic devices;
• Precision agriculture, Quality control, Visual Inspection.

Advantages

• Communication between nodes is obtained without wasting energy;
• Packet losses due to power failure, prevention;
• Backscatter transmissions can be used to propagate the energy state almost for free;
• The protocol regulates the communication between nodes only when energy is available.