Do you have an external pull up resistor to 5v on pin 2?
If not, try setting the pin mode of pin 2 as INPUT_PULLUP.
If the interrupt is only one one pin RISING, you can expect to see 1024/4 = 256 counts per revolution
Do you have an external pull up resistor to 5v on pin 2?
If not, try setting the pin mode of pin 2 as INPUT_PULLUP.
If the interrupt is only one one pin RISING, you can expect to see 1024/4 = 256 counts per revolution