Ok the object is to display the temp in C & F on a 3 digit 7 segment display using the following.
Arduino Uno
Ds18b20 - digital One wire temp sensor
(2) 74HC_HCT595 - shift register
1k resistor network (shown under the LED)
3 digit 7 segment common cathode LED display
SPST NO MC switch
A few other odds & ends (see pic)
Total noob here so all input or better ways to do this is welcome!
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Or go with a LCD in 4 bit mode to save some pins. Lower current as well and you can get nice backlit versions. Then of course you have actual text messages instead of numbers to make it more friendly. The LCD is really easy to use with the library. My son managed to talk to the LCD in only a few nights and he had never done any controller work in the past. Give it a try.
Another possible thing is to multiplex the 8 lines for the LED segments with button scanning. You can scan the buttons so quickly the eyes will never detect you actually turned off the LED's and were using the bits to scan buttons! I've done this type of thing in the past but it adds complexity as you need to add a 8 input/16 output/1 control line mux to the wiring. Use two of these:
