This is actually important! Always use use the Disconnect button in the Telink flasher when finished flashing or updating parameters! It will unpair the BT device and frees it up to do BLE advertising again (and thus be seen/updated in HA).
You can easily detect if the device is still paired by looking at the Bluetooth symbol (upper right on device’s display)—if it’s on, you’re still paired, if it’s off, you’re unpaired and it will do BLE advertising.
Note: As long as the device is paired, it’ll eat up the battery quickly!
Hint 1: To save cost, Chinese factories try to leave out any component the can get away with (I guess it was a cap in this case), resulting in sometimes flakey behaviour. On some HW revisions, expect a very jumpy battery level indication at battery levels below ~40%.
Also, never try to flash it below said 40% battery level! Always use a (relatively) fresh battery.
For instance, I have my bedroom thermometer ~10m away from the next ESPHome BT Proxy, and it has to go through 3 walls. Below ~30% battery level it starts getting jumpy like hell. I’ve set my “battery low warning level” at 10%, so it gives me many battery low warnings…
On the other hand, these are quite nice cheap little devices that work well and can be astonishingly precise. I use PVVX firmware 5.1 with BTHome protocol over BT LE 4.2, usually not modifying the FW defaults (much). My average battery life, using a quality CR2032, is typically 6+ months, even for the ones in the fridge (!) and outside in the patio.
Hint 2: Don’t try to use BT 5—it’s simply not worth the hassle. Phone, tablet, computer, BT adapter or HA might not support it, and you’d have to reset it to BT 4.2 anyway.
Hint 3: I find that the “ready-made project” ESPHome Bluetooth Proxy and the BT Proxy functionality built into some Shelly products work very well. My HA server is a few rooms away (Proxmox LXC) and has no BT adapter.
Note: If you don’t try to “adopt” or “take control” of the ESPHome BT Proxy, it will suggest and perform updates via the HA UI whenever the ESPHome Builder changes—a nice feature.
