Guru
Joined: 07/08/2011
Location: AustraliaPosts: 6455
| Posted: 01:31am 16 Mar 2012 |
I did this for an ultrasonic range detector.
58 uS delay equals 1 cm so a sound frequency of 17241 Hz was used.
Every 100mS, the program sends a start pulse out pin 15 then waits for the return pulse.
The sound output is connected to pin 11 which does the timing.
settick 100, mainloop
waitloop:
if cnt=0 then goto waitloop
if cnt <650 then print cnt*10
cnt=0
goto waitloop
end
mainloop:
cnt=0
sound 17241, 20000
setpin 15, 8
pin(15)=0
pulse 15, 0.02
pause 0.03
setpin 15, 6, begincount
ireturn
begincount:
setpin 15, 7, endcount
setpin 11, 5
ireturn
endcount:
cnt=pin(11)
sound 17241, 0
setpin 15, 2
ireturn
waitloop:
if cnt=0 then goto waitloop
if cnt <650 then print cnt*10
cnt=0
goto waitloop
end
mainloop:
cnt=0
sound 17241, 20000
setpin 15, 8
pin(15)=0
pulse 15, 0.02
pause 0.03
setpin 15, 6, begincount
ireturn
begincount:
setpin 15, 7, endcount
setpin 11, 5
ireturn
endcount:
cnt=pin(11)
sound 17241, 0
setpin 15, 2
ireturn
VK7JH
MMedit