A presently anonymous pair of researchers are working on building a radar HAT for the Raspberry Pi family of single-board computers (SBCs) and compatibles — as part of a smart home project.
"My colleague and I are building a little Raspberry Pi HAT with a radar sensor on it," one-half of the team, identified only by the username "Darkangel-86," explains. "We are going to use it for a smart home project, but we see many other applications for it. Our motive behind building it is mostly privacy-related; we wanted to avoid using cameras. The radar unit can be used to detect respiration, sleeping and movement patterns and we are working on few other scenarios."
Using a 7.9GHz radar module at -42dBm, the prototype HAT — a standard for add-on boards that interface with a Raspberry Pi or compatible via the 40-pin general-purpose input/output (GPIO) header — offers a 10m (around 33 feet) range, and is designed for installation so it's on a ceiling or wall across from the subject to be monitored.
"We think using it as a baby monitor without having a creepy camera is an interesting use-case; it can also be used in bathrooms to monitor occupancy and slip and falls," Darkangel-86 explains. "We've built a little web app to monitor the data stream coming out of the radar HAT. The web app can be used to find trends in the data stream (pretty graphs and alerts and such)."
Thus far, Darkangel-86 has not published any source code or design files - nor indicated whether the prototype design is likely to make it to production as a purchasable product. More information can be found on the project's Reddit thread.