3 Home Assistant projects to unlock hidden hardware features this weekend (Oct 2-4)

Published Oct 4, 2026, 8:30 AM EDT Adam has a degree in Engineering and has a life-long interest in technology. He has been writing for over a decade for various print and online publications, with a focus on consumer tech. He joined How-To Geek in 2024 while working at Pocket-lint. As well as being a long-term fan of Apple products, he also has a strong interest in smart home tech, running a Home Assistant server at home to automate all his smart home devices. He believes that the ideal smart home should work with minimal interaction from the user, with automations running as if by magic rather than requiring you to push buttons on a control panel. You can find more of his work on Muck Rack. Credit: PawHut It's usually the case that when you want to add capabilities to your smart home, you need to invest in new hardware. Sometimes, however, you can take a different approach with existing devices that lets you replace the firmware, not the hardware. Doing so can remove cloud dependencies, expose hardware that wasn't previously accessible, and even enable capabilities that the original firmware didn't offer. Give a pet feeder a new brain You can flash the ESP32 inside with ESPHome Credit: PawHut The ESPHome website has a large list of compatible devices that can be flashed with the ESPHome firmware. It covers everything from smart plugs and light bulbs to garage door openers and EV chargers. There are setup guides and configuration templates that you can use with each device. One of the devices on the list is the Petkit Fresh Element Solo Pet Feeder, which is an automatic dry-food pet feeder designed for feeding cats and dogs. You place the food into the pet feeder, and it will dispense appropriate portions into the bowl on a set schedule. Since the device is powered by an ESP32, it's possible to flash ESPHome so that you can add the pet feeder to Home Assistant. Flashing the device requires some effort. You can't do it with over-the-air (OTA) updates; you need to open the device and use a USB-to-serial adapter to flash ESPHome. There are disassembly and flashing instructions on the ESPHome website that walk you through the process. Once flashed, the pet feeder can become a native Home Assistant device without relying on Petkit's own software for Home Assistant control. The supplied configuration exposes options such as manual feeding controls and how many scoops are dispensed, while still allowing you to control the feeder with the physical buttons. Scheduling can also run locally rather than relying on Petkit's cloud. Opening and flashing the feeder does come with the risk of damaging or bricking the device, and there are two different circuit board revisions, so you'll need to ensure you follow the instructions for the correct one. However, Home Assistant users have reported successfully flashing ESPHome and controlling the feeder locally. Replace a Shelly smart plug's firmware without opening it up You can use Shelly's own OTA firmware updater The Shelly Plug US Gen4 is a Wi-Fi smart plug with power monitoring. Shelly is a popular brand with many Home Assistant users and is part of the Works with Home Assistant program. Several Shelly products have been certified as being compatible with Home Assistant and meeting the program's requirements for privacy, local control, and sustainability. Some Shelly products can offer more local control than typical cloud-based smart plugs. However, if you want even more control, you can flash the smart plug with ESPHome. ESPHome exposes the relay for the plug, as well as power, energy, current, voltage, and frequency data. It also gives you additional options, such as the ability to control the plug's RGB LED ring, which you can use to visualize power consumption or indicate connectivity status. The beauty of this project is that you don't need to take the plug apart to flash ESPHome. The firmware package can be flashed to the device over the air using Shelly's own update interface that you can run from your browser. The repository includes firmware for several Shelly devices. You do lose Shelly's stock features, and the custom firmware comes with a warning that you use it at your own risk. You can also access many of the exposed features through Shelly's own API to achieve the same results. Make a Xiaomi Bluetooth sensor into a Zigbee sensor Changing the firmware can even change the protocol Credit: Xiaomi This project doesn't just change the features of a device by replacing the firmware; it changes the entire communication protocol that it uses. The Xiaomi Mijia Smart Digital Hygrometer 2 is a cheap temperature and humidity monitor with an LCD screen that communicates over Bluetooth Low Energy. By flashing custom firmware, it's possible to convert this device from Bluetooth to Zigbee. That's because the device contains a multi-protocol 2.4 GHz radio that supports both Bluetooth Low Energy and the IEEE 802.15.4 radio standard that Zigbee is built on. It's the Xiaomi firmware that tells the device to use Bluetooth, and since the radio is also compatible with Zigbee, replacing that firmware can turn it into a Zigbee device. The exact method depends on which version of the device you have and the firmware it's currently running, but in some cases, you can flash the firmware over the air from a browser without having to open up the device. You can then add the device to Home Assistant using Zigbee2MQTT or ZHA. The device has been around for a long time, and there are multiple hardware and firmware revisions. OTA flashing won't work for every revision; for these devices you'll need to open them up and use a USB-to-UART connector. You also may not be able to tell exactly which hardware and firmware your device has until you've bought it. Sometimes new firmware is all you need Before you go out and buy yet another smart home device, it's worth taking a look at what you can do with the devices you already own. New firmware can not only unlock new capabilities; it can even make your device use a completely different protocol. You may find that making the change is as simple as flashing the firmware over the air.