Shoulder Angel

An ultra-low-power, open hardware platform that acts as a watchdog coprocessor, ensuring remote recovery and reprogramming of wireless sensors despite fatal software errors.

Shoulder Angel is a critical, ultra-low-power platform for managing low-power wireless sensors: it guarantees deployability and maintainability. The system uses a physically separate coprocessor to continuously monitor the target sensor's power consumption and behavior. This design allows it to detect and recover from fatal software errors—like infinite loops—that would otherwise prevent wireless reprogramming and require costly human intervention. Developed by researchers including Nicole Tobias and Josiah Hester, Shoulder Angel keeps the device in a reprogrammable state, performing this vital watchdog function with an efficient energy overhead of only 7 µW. This capability is essential for long-term, maintenance-free operation in IoT and embedded systems.

https://www.clemson.edu/cecas/departments/cs/people/faculty/sorber/pubs.html