Ultrasonic Anemometer

[seandepagnier]

K JSON on the fly. Another Member suggested the manufacturer could supply a faster data stream, since they have an extensive design team in-house. 10Hkz was suggested by some Racers. A small solar cell/Lipo Battery might be enough to power the anemometer without any wires at all.

2) Accuracy your previous experience with mechanical wind sensors is excellent. "..Feel the wind & rain like the sails" sounds very correct to me.
For an Autopilot, such as pyPilot or your own, wouldn't a tilt sensor (9-axis accelerator), magnetic compass andlot GPS heading also be part of the algorithm? My mechanical Monitor Wind Vane 'autopilot' does the tilt compensation with a clever weight design and the boat's motion.

yes, pypilot generally follows a compass course all the time, and in wind mode adjusts the compass course to meet the commanded wind angle. This allows for a slow filter of the wind data. The "wind pilot" does something different but this is still experimental. So it is part of the the algorithm of course but not my point.

My point is, the ultrasonic anemometer discussed for $139 is clearly designed intended to be mounted vertical. It is not designed to take wind from an angle. So if the boat is heeling, the wind will flow through the sense area at an angle which creates much turbulence and it is doubtful that the readings will be accurate.

May I ask your suggestions for a mechanical wind speed sensor? Ray-marine now sells "my idea", LoL.  They call it the Rotovector Z195. The the "cups" sense speed & direction with a non-linear cup design and an Index Pulse.

This is the worst design I have seen. It is incredibly inaccurate for wind direction, and similar to the "peet bros" design only worse. The the wind direction is not accurate enough for even basic use, and in lighter winds the accuracy decreases more. It is not even close to good enough for an autopilot.

I have 3d printed anemometers I hope to provide kits at some point. Mine are accuracy to 0.1 degrees, but I admit ultrasonic is in theory better in some ways but seems to have shortfalls.

I agree to use a dedicated esp32 to receive BT from wind sensors and this wired to the pi's pins or even just via usb rather than use the pi wifi which is not deterministic.