I bought a few of the Switchbot Meter Plus temperature/humidity sensors when they were on sale, to put one in each room and use them to control my heating.
They "broadcast" everything shown on the screen as BLE service-data which means you can passively read it at whatever interval.
I didn't want to sign up to their cloud with the app where they collect all of your data (my HA is offline, that's how it'll stay) so I built a BLE<->WiFi<->MQTT device using an ESP32 and a firmware I found on Github, with some modifications; it scans for the devices by BLE address, reads the service data and publishes it to the MQTT endpoints used for HASS.
FWIW, if your HASS is running on a device (like a Raspberry Pi) that has Bluetooth, you might be able to get away with a custom component like https://github.com/custom-components/ble_monitor instead. Of course, if your setup is working for you already there isn't much incentive to change it.
Anyone serious about running HASS, or home automation in general should move away from a Pi because it's not cut out for running a home, the SDs are fragile and need decent, clean power and the performance isn't stellar when you've got a lot going on.
It's a nice, cheap starting point, but something like a NUC or similar is the next step for a reliable machine to run it on and won't suck up electricity.
They "broadcast" everything shown on the screen as BLE service-data which means you can passively read it at whatever interval.
I didn't want to sign up to their cloud with the app where they collect all of your data (my HA is offline, that's how it'll stay) so I built a BLE<->WiFi<->MQTT device using an ESP32 and a firmware I found on Github, with some modifications; it scans for the devices by BLE address, reads the service data and publishes it to the MQTT endpoints used for HASS.