Hello everyone. I want to measure distance sensitively with HC SR04. For example 15.262 cm-15.263 cm- 15.264 cm. How can i increasing sensitivity of it? pulseIn is for microsecond but i need nanosecond for it. How should i change duration formula for it? Thanks.
duration = pulseIn(echoPin, HIGH);
distance= duration*0.034/2;
What for??? Why??? The sensor's accuracy is 0.3cm!!! All the rest is just a noise, echo etc. You can't trust any number after the dot.
You can slightly increase acuracy by using median filter & compensate embient temperature. Check this - GitHub - enjoyneering/HCSR04: Arduino library for HC-SR04, HC-SRF05, DYP-ME007, BLJ-ME007Y, JSN-SR04T ultrasonic ranging sensor
For example 15.262 cm-15.263 cm- 15.264 cm
That is not possible because the wavelength of the 40 kHz sound pulse is about 0.75 cm. The very best resolution attainable is about half that.
Get a VL530x or a similar sensor.