PCB and components
PCB is common for counter and digital scale:
It is TWO SIDE COPPER PCB!
Components placement (digital scale has a few ones, which aren't necessary for counter):
Notes:
- PCB is the same for both common cathode and common anode variant (copper
foil must be broken at both sides of transistor array and vired with +5V
in case of common anode variant.
- common anode switching transistors are of PNP type (best solution is to
take low power switching transistors),
- resistor from pin 3 of decoder 4051 should be grounded,
- source code should be slightly changed
(Changes are in the source code commented. You should uncomment them and comment "cathode" blocks.)
- Digital scale differs only in components it needs. For reference see schematics.
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