ultrasonic sensor and uno

Projects Programming
1

i have a hc-sro4 ultrasonic sensor and can only use pins 9 and 10 with it on an uno.
On a funduino mega none of the pins work with this sensor.
Anybody know why?

2

Wired wrong?
pinMode() set wrong for the two pins?

Show your code and describe how the sensor is wired.

3

None of the pins??

There is NO 1:1 pin mapping bewteen the Uno and the Mega. Pin 9/10 on the Uno are PB1/PB2 but PH6/PB4 on the Mega.

Try pins 20/21 for PB1/PB2 on the Mega.