First open a terminal. Type:
$ halrun
now, after you've plugged your joypad, load the hal_joystick component (I will assume that the address of your joypad is /dev/input/js0, the default if you have only one joypad attached):
halcmd: loadusr hal_joystick -d /dev/input/js0 -p joypad
now we load one halmeter to check the axes values:
halcmd: loadusr halmeter
the little halmeter window should open, click on select and you will see all pins created by hal_joystick:
select the first axis, and click apply; now you should see the little halmeter window shoving the value for that axis:
If it is 0 and you are not moving the joypad, everything is fine. Try to move your joypad in order to see which is the axis.0 You can check all other axes if ou want, however if the first outputs the right values, others should do the same. If things are not that good, you could try to calibrate your joypad using jscal (install the package joystick from synaptic)