I am interested in building a "selector" gadget for devices that take jumpers to select a program, such as this game cartridge where you have 5 jumpers to select program #0-31 (the jumpers represent the binary number):
The selector would have two 7-segment LEDs that display the currently selected program number (0-31), and a couple pushbuttons (+/-) that let you increase/decrease the program #. The device translates the number into binary and turns on/off the appropriate switches or relays which are attached to the jumpers on the device (ie the above game cartridge).
Or I would even like to build a kind of analog to digital converter device which has a potentiometer (for example 100k) which gets translated into an 8-bit number (0-255) and 8 switches get opened/closed that represent the value of the pot. Adding three 7-segment LEDs to display the current value in decimal would be cool and then it could be used as a "selector" as well.
Does anyone know of any plans or schematics out on the Web to construct something like these? (For now I just wire switches to the jumpers.)
Thanks.