I believe that this is the only ultrasonic anemometer on the web which hasenough detail to enable it's actual construction.
1) Where do you get the formula v = SQRT((d/t)*(d/t)+(C*C)) - d/t ?
1)Why the 300 samples ? I see you explain and show math about the 3 seconds and get 312 samples to produce 1 measure.You can use just 100 samples or even less and still get good results .
2) Why are you mention to get TOF in multiples of 25 usecs (instead of real time)? You send the pulses (actually 16 )and should be able to get the time to arrive. You could send the pulses , start timer and stop when it arrives .
3) I am not sure to understand why you use the 74HC368 drivers? Could you use just the I/O pins of the microcontroller directly?
4) What do you use zero detector and envelope for ?
1) What do you mean by "largest" /"smallest" TOF . So this formula is based on "large" number of samples and I pick largest and smallest and substracts them to get "t" ?
i still do not understand the big picture of you method to determine the wind speed
In your code i see you use TCNT1
why the ZCD has a pot R 22 ?
D1 , on the envelope detector.
On the 4052, why we need -5 V?
What I mean if we send pulse 1 , the corresponding reversed pulsed will be after 300 other pulses
It looks like if the diff is less than 200 (ie half period), then you add a pulse.
about transducers behavior and define Northerror .
Even you mentioned that we do not have individual Tof, I think we do have it, since envelope measures that
My question to you is how do you know that this is needed?
pick the signal from the sending end
it gave me unreal and constant values
two pin one is short and another one is long