Perhaps but the SRF04 is the most commun not the ultrasonic seeedstudio.
you find very easy an SRF04 but if you want to use a seeedstudio, you must buy on the url seeedstudio. Else you have a good luck to use a real SRF04.
I buy many SRF04 on many dealer and all my SRF04 works with 4 pins and not 3 pins.
i think many people have a problem with the sensor because, they don’t use the seeedstudio ultrasonic.
I will buy a seeedstudio ultrasonic for my test.
And also, on seeedstudio, they have an error:
see the schematics with SRF04, they use D8 and D9 for the signals and VCC and GND !!!
perhaps make 2 commands for the ultrasonic sensor: 1pin and 2pins