Extra joystick buttons for the minimigThe
minimig is a great project designed by only one man: Dennis van Weeren.
Today lot's of other people are making imporvements on the publicly
released code of the minimig which is great because this means that new
functionality is added and bugs (if there were any) will be fixed.
nice example of the extra functionality of the minimig is extra
joystick button(s) to improve usabillity. By adding an
extra button to your joystick, you can controll your complete
your joystick from your lazy chair. The
joystick below has the left button connected to UP&DOWN, when
pressed the minimigs OSD menu pops up (or close if allready open) and
then you can easily and navigate through the menu using the normal
joystick controls up/down/left/right. To select any option, press fire
button. This joystick mod works from version FYQ100818 & PGL100818
Because I always like symetrical design I added 2
buttons, one that combines UP & DOWN (pops up the OSD menu) and one
the combines LEFT & RIGHT. The last one has no function yet but
perhaps in the future this will be added, I do no know. I think the
extra buttons look cool. The UP & DOWN button works like a charm
and now I never need to walk toward the minimig from my lazy chair to
enter the OSD menu to swap/select a disk.
But how do these extra buttons work and how does this look like. Below some photos of my modded joystick.
How does it work:Well
actually it is quite simple, it is impossible for the user to move up
and down at the same time. It is also impossbible to move left and
right at the same time. So these combinations are unused by every
joystick ever used on the Amiga. This is great because this means that
we can use these digital combinations of signals to indicate the state
of another button. The only thing we require is 2 buttons and 4 shottky
diodes (I used the BAT54C, that is a 3 pin device that holds 2 shottky
diodes with their Cathodes connected). The diodes are required so that
a simple single throw button can be used. But if you have a double trow
button lying around then you do not need the diodes. The diodes simply
prevent that up and down (or left and right) are shorted during the
time that the button isn't pressed. One more thing about the diodes,
they have to be shottky. Shottky diodes
have a very low voltage drop of approx 0.2V if you use
standard diodes the voltage drop across the diode would be too
high and the mod simply won't work.