Hello,
the RCWL-9600 is very accurate.
You may read the data using a simple function like this:
#define M5_I2C_ADDR_ULTRA 0x57
float ReadI2CDistance()
{
uint32_t data;
Wire.beginTransmission(M5_I2C_ADDR_ULTRA);
Wire.write(0x01);
Wire.endTransmission();
delay(120);
Wire.requestFrom(M5_I2C_ADDR_ULTRA,3);
data = Wire.read();data <<= 8;
data |= Wire.read();data <<= 8;
data |= Wire.read();
return float(data) / 10000; // distance in cm
}