I found this cool IBM joystick at an electronic components store. It takes me back to just being born. Anyway as newb, how do I begin to figure out how to connect this to my arduino?
So far I have 'arduino2flash' and Flash working for me so I can listen for stuff and get readings easily. I'm just not sure how to figure out what is ground, data, etc.
Looking at the plug, I see 8 holes/pin slots, one slot is covered with plastic, and another is empty looking with no metal inside. I'm amusing there are 6 pins.
The joystick moves as if it has two potentiometers. There are two push buttons, and two rotating dials on the sides of the joystick (not sure what their purpose is yet).
I'm taking out the screw driver shortly!
Thanks for any advice in advance.
Whoa! This is so primitive, even I can figure it out. Nevermind. :)
yea its super easy, just 2 pots and a button
in the pc the 2 pots control the duration of 2 single shot timers (actually a quad 555 for 2 player or a flight stick) , but on mcu's you can just use analog in
btw nice retro find
Awesome, and thanks! I figured the older, the better to learn from. Also my Flash simulator I’m creating has an older feel, so the hardware and software play well together.
Any thoughts on why the potentiometers only have two wires connected instead of three?
yea its connected like a rheostat, its just like a normal resistor if it had a knob on top, which changes the charge rate of the cap on the quad 555 timer, thus effecting pulse duration (apple and commodore and many other systems that used analog controls do the exact same thing)
for use with analog connect the 3rd pin to ground and now it should be acting like a voltage divider, OR if you dont want to muck with retro add a resistor on the other end
joy out --- |---/\/\/---gnd
Cool. Your little text picture makes sense. Thank you for tip. I don't mind adding a resistor before hitting ground. Question is, how much should I consider? Bigger resist before ground = bigger reading by arduino? I could throw 10,000R or 330R - 990R at it. hmm.
the pots should be 100k on pc (150k for pretty much any other retro system)
you should start by matching that
Thanks again! I think I'm set. All my wires are prepped and I may ground things until tomorrow anyway.
still jealous, that thing would look so pimp next to my 1987 model M keyboard
thats before restoration, now theres no school paint on it and it lives on my main computers desk, best 3 bucks i ever spent
If you add a resistor to your outside circuit instead of rewiring the pots as dividers, then you'll have to do some math on your ADC readings. The voltage will not change linearly with stick position.
I always add the third wire to the pots...less work overall.
The reason they were ever set up as rheostats instead of dividers? ADCs used to be pretty expensive. It was a lot cheaper back then to time how long a cap charged through a resistor. To save a buck, the world instead suffered through decades of joystick calibration.
I see what you mean:
However, adding ground wiring may be more of a challenge on the cool factor part. I'll try the math first to keep it looking neater first, then go to plan B. Thanks for the great clearification on what to expect.
there's already ground in the joystick, for the buttons to pull down to
you just need to connect it and never use it on a pc again, thats the tidiest way, and you can always remove it if vintage analog pc joysticks become the new gold standard tomorrow
Ah nice! I do see a common connection between the two buttons. I'm guessing that's gnd.
The only other pieces I'm trying to figure out are the blue pieces the two button brown wires connect to, and the two red potentiomenter wires connect to. I'm looking it up. Could they be resistors?
Thanks again, and yes your 1987 keyboard rocks! 8-)
EDIT: *pots, I'll start using that.
cant really tell from the pic's, my (much newer like mid 90's) joystick doesnt have them, probably caps to filter noise on the power lines
blue is a fairly common color to film capacitors (along with green and red, not sure if there's a color code hidden in there)
That would make sense. Good advise.
I'll post an update when I get this thing working (or if I end up in the emergency room). ;)
as someone who has been hit by a flyback transformer or 2 in crt monitors, a few times by 120volt mains, and once by a 220volt air conditioner while standing barefoot on concrete i have to say
if you end up in the emergency room over 5 volts and a ~quarter of an amp, you really really screwed up! ;D
Cool find with the retrostick, also loved the input on the analog vs rheostat comparison. That's the stuff i like to find, info about why some paths might be better to take with development of a circuit. Another noob friendly trolling find for me!
a member of avrfreaks published his work on something related, that might be interesting to some of you
You're right I'd have to trip and land my eye on the joystick or something to end up in the emergency room. :o
Dang that's a lot of voltage you speak of!
yea well everyone i think has grabbed 120, the flybacks were when i was a teenager and careless while repairing them
and the air conditioner, well did not see that one coming!