I'm building a joystick type device (actually it's a HID Dj software controller) with many inputs 80 analogue & 160 butons on a Uno R3, I did the hard bit with the HID firmware, I'm on to the next hard bit : picking the parts.
I'm new so I'm a bit daunted with some of the technical terms and range of choice when shopping.
The analogue muxing, I think I have the right choice with 5*
http://uk.farnell.com/analog-devices/adg706bruz/ic-mux-16ch-smd-tssop28-706/dp/9604332
With a on resistance of 2.5 ohm it's ok with respect to the 10 k that will be providing the variable potential
(If I could find a DIP 16:1 or 32:1 with a low on resistance I'd rather have that)
For the buttons, 20 shift registers seems the way to go, of these 2 which should I go for? can these be daisy chained?
http://uk.farnell.com/texas-instruments/cd74hc165e/logic-shift-register-8bit-hs-16dip/dp/1740096
Shift register with a IC output type of differential ???
Or
Shift register with a IC output type of Standard ??? (I don't know what this means, wikipedia got very technical very quickly)
Or have I got the wrong type in both choices?
I've read I need 0.1 uF ceramic caps for the shift register's power supplies do I also need them for the muxer's supplies? (I'm guessing yes)
For a pull down resistor(s) for the buttons what is a sufficient ohmage? (does it matter? anything +1k? 1/4w)
Pots will be 10K linear and buttons will be cheap.
Have I missed anything for consideration? Thanks for reading and looking if you did.
nick