so overall 2 micro second is the difference ..though it will not add much difference at all.
second thing is that - the sound speed varies at different temperature and humidity
at 0 degree- 331m/s
i was taking the value 347 m/s which is at 30 degree.
real temperature is 35 degree , so i also taken it into consideration 331m/s + 0.6*temp ==> 352m/s at 35 degree
that has reduced the error ..significantly
should i take humidity factor also into consideration ?
https://sciencing.com/humidity-affect-speed-sound-22777.html
as per the above link - sound travels about 0.35 percent faster in 100 percent humidity.
current humidity is 81 percent ,...(considering close to 100 percent) should i add 0.35 percent of 347m/s(velocity at room temp) ?? // as per the above link information.
final sound speed will be = 352+ 0.35% of 347
= 352+ 1.21
= 353m/s
is there anything else which i should take into consideration??
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commuation time is a value in nanosecondes !
you have air speed velocity of U.S.
5.88 µS/mm
so , not a problem with any nS even with 1µS .!
if you have not inserted RC filter .
no ,i am not using any RC filter,
yes, even `1 uSec will not add any significant error .
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Hi,
no voltages?
I have to guess.
* From rising_echo to uC_falling I expect less than 1us
* From falling_echo to uC_rising I expect more than 1us (mainly depends on echo_LOW_voltage (real value) and stray capacitance on bjt_collector)
Klaus
vcc is 5 volt.