4 impressive presence-sensing ESP32 projects to build this weekend (Aug 28 - 30)

Published Aug 28, 2026, 11:15 AM EDT Tim has been covering technology for almost 20 years, in that time spanning a broad range of topics from security to product reviews. He is especially focused on the Apple ecosystem, productivity, and consumer advice. Over the years Tim has written thousands of articles, reviews, and round-ups in addition to producing video content and original photography. A graduate of journalism, he found his footing as a freelancer with a laptop and loves how he is able to work from practically anywhere. Now a Senior Editor for iPhone, Mac, and Smart Home at How-To Geek, Tim still loves to write. He can also be found crafting round-ups and productivity posts for the Zapier blog. Earlier in his career Tim spent nearly a decade as a writer and eventually Apple section editor for MakeUseOf. Tim currently lives in Brisbane, Australia. Outside of work he loves to hike and work out, play video games, and spend quality time with his wonderful partner and two cats Inka and Roger. Looking for a way to detect presence in your smart home? You could buy a ready-made presence sensor, or you could build something yourself that’s powered by the mighty ESP32 microcontroller. All of these solutions should work a treat with Home Assistant. ESP32 mmWave Presence Sensor This project should be on your radar Credit: DFRobot mmWave presence sensors use radar to detect presence for targets that are moving or staying still (and everything in between). They’re more reliable than infrared sensors, and they won’t cause the lights to go out simply because you’re only making small movements when sat down in a chair reading a book. They can even detect your presence when you’re completely still, like when you’re lying in bed. There are some good mmWave presence sensors on the market, but you can also build your own using a few off-the-shelf components. One Home Assistant Community user has put together a DIY presence sensor that uses the ESPHome platform combined with a C4002 radar module that works on two frequencies, an ESP32-C6 development board with Thread and Zigbee, and some other simple components like USB cables, jumper wires, and a power supply. This works best when plugged in at the wall, since mmWave presence detectors are far thirstier than their infrared counterparts. One upside to the technology is that mmWave should work through surfaces like drywall, wood, or paper—so you can hide your sensor behind a picture frame or similar. Bluetooth proxies for Home Assistant Detect presence and do other things A Bluetooth proxy is a device that communicates with your Home Assistant server using Wi-Fi and acts as a bridge to talk to any Bluetooth devices you might want to use. A Bluetooth proxy can allow you to control Bluetooth-only devices without worrying about the Bluetooth range on your main server. Projects like Bermuda and ESPresence can be used in a similar way for room-level presence detection. By following the Bluetooth signature of personal devices like smartphones and smartwatches, Bluetooth proxies can gather your current location based on the strength of the signal. If you’re trying to pick between them, Bermuda relies on ESPHome to run the show so you can also use the Bluetooth nodes for other things too. ESPectre Open-source router-to-device motion detection over Wi-Fi Credit: francescopace / GitHub ESPectre is an ESPHome project that analyzes Wi-Fi interference to detect motion. It works through walls and furniture, much like mmWave, though it doesn’t rely on images for this to work, so it maintains a decent level of privacy. A range of microcontrollers are supported, including the S3, C6, C5, C3, S2, and vanilla ESP32. You only need a single correctly placed ESPectre device for this to work, though the more you have, the better your coverage. Motion is detected by analyzing interference between your router and ESP32, so you might find yourself having to be a bit creative to get broad coverage of your home. ESPectre cannot differentiate between movement caused by humans or other sources, nor can it detect static presence. Once you have an ESPectre node or two, you can play ESPectre The Game, where you must stay still or move quickly to win. It’s a neat way of showing off the technology, though the real utility comes from smart home integration. TOMMY Closed-source device-to-device motion detection over Wi-Fi TOMMY is a lot like ESPectre with a few key differences. Unlike ESPectre, TOMMY is a closed-source project. There’s a free version available, but it has limitations. It only supports a single zone, and detection is paused for a minute every two minutes. It’s a way of testing the product out before you pay the one-time €49 licensing fee. You need at least two TOMMY nodes, and the more you place, the better the system becomes. You can define multiple zones, since TOMMY detects Wi-Fi fluctuations in the space between nodes (your router isn’t used apart from communicating with your Home Assistant instance). TOMMY supports static presence detection and has planned support for detecting human and non-human movement patterns soon. TOMMY works on a wide range of ESP32 devices including vanilla microcontrollers, S2, S3, C3, C5, and C6. Once you’ve set up presence detection, you can use it for all sorts of things.