This guy gets the best battery numbers. His ESP32 “Trig Board” spends its time off and is triggered on (by a RTC or sensor) sends a message, then turns off.
https://www.tindie.com/products/kdcircu ... -platform/

The internet is buzzing over some new silicon in a MCU from the Raspberry Pi foundation.
But this only emphasizes how far ahead the ESP32 was years ago. And may still be. Really. The M0+
Not perfect. The ADC and in-circuit debugging are troublesome.
But it has a radio in it!

So, as per my understanding, that UUID is generated by iOS based on some hardware property of the BLE device (e.g. MAC address).

Probably not. The point is how it was derived is unknowable and probably not deterministic.

16 bit UUIDs are standardized and published by the Bluetooth SIG. So they are known before-hand. They deal with measurements of health, time, temperatures, velocity, etc. Standard stuff useful for everybody. Nobody could publish all the 32-bit UUIDs. There are more of them than there are stars in th...

OSX Catalina was the last version I got to work.
Big Sur is locked down to the point of being pretty useless for our tool chains/apps.
I Dual boot.

Ooooops.
Some Callback processing causes a crash.
Stack size somewhere in Arduino version needs increasing I guess.
The troubleshooting costs might exceed the benefits.

Thanks. I completely missed NimBLE. I saved about 6% program memory. Using BlueDroid Sketch uses 1095047 bytes (16%) of program storage space. Maximum is 6553600 bytes. NimBLE Sketch uses 656243 bytes (10%) of program storage space. Maximum is 6553600 bytes. Notes: If you are using the Arduino re-fa...

A google search turned up this 90+ projects summary.
I haven’t verified everything but I think they have a good reputation.
https://randomnerdtutorials.com/projects-esp32/

but also there is the same usb engineering sample to the maker market with an ESP32-S3, which support Wifi and Bluetooth and is based on the ESP32-S3-Mini serie's.

Can’t wait for any news on S3—mini or maxi

Thank you for all your work on this.