Is there a way to measure the speed of the propeller (rpm)with a multicopter? 
The Adulpilot site says that there are the following three methods. Does anyone actually do this?
1.Hall effect
2.Electrical commutation
3.Optical
It’s simple with BLHeli_32 ESC’s and ESC telemetry.
Currently, it is equipped with readytofly2212 920KV cw ccw brushless motor 2-3 s + 30A simonk esc.
BLHeli_32 Can I measure without ESC?
SimonK and BLHeli_32 are mutually exclusive. That makes no sense. What ESC’s do you have?
This will be available in Master soon and is another way to calculated RPM from the Notch Filter FFT function.
The ESC installed is “Simonk 30A”.
Does it mean that the Simonk 30A cannot measure?
No, it cant. You need BLHeli_32 ESC’s for ESC telemetry which will give you Voltage, Current, RPM and temperature. No one should be using SimonK firmware ESC’s these days when BLHeli_32 ESC’s are available for relatively low cost. They are more efficient and smaller in size and weight for the same current capability.
Is it possible to measure with BLHeli_32 ESC?
Yes. As I have already said.
Thank you very much.
Should I buy “150kbaud DShot150” for BLHeli_32 ESC? It says that I will visit the Adulpilot site.