Tried this but without result:
main:
high b.1 'push TX speaker out
delete-!!pulsout b.1,200-- It is supposed to self resonate at it's natural freq
'generates a 2 ms pulse
delete-!!low b.1 'let speaker resonate at38 khz NOT stop it by making lo
pulsin b.1,1,b1
if b1>0 and b1 < 10 then high b4...