To track if my electric bike is at home I want to add some kind of tag to the bike.
It has to be battery supported and I guess working on wifi. Zigbee based devices seems a deathend (see Use a zigbee device as presence sensor? ). And in the garage HA bluetooth is not getting there…
There are some wifi sensors (for example with temperature sensor) on batteries that could serve but I don’t find any that supports HA.
Requirements are basically to see that the bike arrived at home; 10-15 minutes delay is acceptable. I can put the tag in a bag on the bike (no need to glue it ;-)).
You should rethink this. WIFI is very battery hungry.
Set up a ESP32 on bluetooth proxy instead and add a bluetooth tag on it.
That will give you a much better battery life
Wifi doesnt need to be power hungry.
I have a wifi co2 sensor from airthings that can run for 2 years on batteries.
If wifi is constant ‘on’ I agree the power consumption is too high for batteries. That is why i am happy with 10-15minutes delay.
But a bluetooth ‘hub’ is also an option.
Building them myself is a step too far.
You connect a USB cable with one end in the computer and the other end in the ESP.
You flash it with ESP-Home.
Add BT_proxy in the yaml and flash again.
And the devices from m5stack look “tidy” rather than a board needing a case (eg. atom echo/lite or m5stamp). The flashing is even easier - the ESPHome page has a bluetooth proxy as a ready-made project - you plug it in and connect to flash from the browser. You can also get presence detection from the same device using (amongst others) Bermuda.
The only WiFI tags I’ve seen also have SIM cards and require monthly subscriptions for detailed location data. But in general, WiFi makes for pretty lousy presence detection because the device has to keep going into low-power sleep to preserve battery, which drops its network connection and it looks like it’s gone.
BLE tags are much more effective, and there are quite a few products for sale running ESPhome on esp32-c3 modules out of the box (including this Athom Plug and Energy Monitor and a soon-to-be-released presence sensor) that can be easily upgraded to enable the bluetooth proxy feature. Many Shelly (Pro, Gen3) products also have bluetooth proxy out of the box if you’re not ready for a (much cheaper) DIY approach.