Your sketch doesn't compile:
/Users/john/Documents/Arduino/sketch_sep22a/sketch_sep22a.ino: In function 'void loop()':
sketch_sep22a:17: error: expected primary-expression before '==' token
if (LOW) == digitalVal)
^
exit status 1
How is your tilt switch wired?
Did you put an external pull-up or pull-down resistor on your input pin?