I bought an adxl345 a while ago. This week i had the time to solder it and tried to get this thing to work.
First: i think it's somewhat broken. Output for each axis under normal conditions should between -255 and 255, with 4mg each step. E.g.. If it lay on table x and y should be around 0, z -255. Mine shows y=-320 and z=1500. Values ranges are about +-320, which is to high i guess. Tried many different tutorials, examples, inits. Even the Adafruit library - which i want to avoid, because it's a very cheap noname module.
But except that, it works
So, the first thing I made was a "water level" (wasserwaage). Second i took the circlephysics example (like rodot??), put a hole in the middle in which the circles disappear - et voila, a game
To come to a point: the adxl345 is a nice thing, but maybe each game using this should have a calibration routine