A very simple Python interface to SFR05 ultrasonic module
GPIO.setmode(GPIO.BCM)
sensor = SRF05(trigger_pin = 15, echo_pin = 14)
while True:
print(sensor.measure())
prints didtance in centimeters.
The SRF05 and Python combination are only good for really simple use cases, basically to experiment and play with. The nature of SRF05 requires accurate measurement of time which just cannot work reliably if you go beyond a simple example. The moment you start loading your CPU with other processes or start using threads in your Python application, it will start affecting your measurements.
You need to be prepared to treat SRF05 readings as raw data, filter outliers and all that.
If you want reliable distance measurement that is not affected by other threads/processes - the simplest solution is to get a distance sensor that times the echo response internally and gives you the distance value via a digital interface like I2C.