scanning BCD switches

[dsicon]

thanks all
i like the single pin ADC approach, seems like the least stuff
i am already doing pushbuttons this way

too bad there are no res values in the MC app note #7, guess that would spoil the fun

but on 3 bcd sws there would be 1000 combinations, strikes me as too touchy for a 10 bit AD, or am i missing something ?
ds

[Darrel Taylor]

but on 3 bcd sws there would be 1000 combinations

But I'm sure you only need 512 of them.

Yeah, I think reading all 3 BCD switches on 1 A/D might be a stretch.
But with each digit on different pins, 3 pins would be better than 7.
Then there's only 16 voltage possibilities per pin (10 used). Piece of cake for A/D.
<br>

[amgen]

ds,
Do your switch readings need to be checked often, rearly, only once ?

don
amgen

[dsicon]

ds,
Do your switch readings need to be checked often, rearly, only once ?

don
amgen

they will either be polled at the top of the main loop or in response to a button push, haven't started the program yet

it looks like i will be using the 7 pin diode matrix approach after all since it seems to offer the best set of tradeoffs given other considerations in the design, i just really don't like stuffing the 12 diodes due to insertion cost
oh well