RE: Raspberry Pi Pico multicore demo using HC-SR04 ultrasonic ranger and a 4-digit 7-segment display

robogary — Sun, 29 May 2022 14:59:10 GMT

Nice here is some Ping code without using a specific library.

PingTrigger=Pin(9,Pin.OUT)
PingEcho=Pin(8,Pin.IN)

def Ping():
echotries=0
PingTrigger.low()
utime.sleep_us(2) # note sleep_us is for microsecs
PingTrigger.high()
utime.sleep_us(10)
PingTrigger.low()
while ((PingEcho.value() == 0) and (echotries<30)):
EchoStartTime = utime.ticks_us()
echotries=echotries+1
# This check bails out of the loop on a problem with a long echo or failed echo, I havent been able to prove its needed.

while PingEcho.value()==1:
EchoHeard = utime.ticks_us()
PingDeltaTime=EchoHeard-EchoStartTime
PingDistance_cm =(PingDeltaTime*.0343)/2 # sound is 343.2 m/s .0343 cm/usec
PingDistance_in=(PingDistance_cm)/2.54
#print ("Measured distance is ",PingDistance_cm, "cm" )
print ("Measured distance is ",PingDistance_in, "inches" )
#print ("Echotries =", echotries)
return PingDistance_in