eng.mak88
Newbie level 4
So I constructed this Tachometer project (it can measure RPM using 3 methods but I just chose one of them which is by IR LED and Photodiode) and I'm really sure that I did it right according to the circuits schematic I got from an electronics magazine, but when I connect the power supply its just dead and nothing works at all, please look at both circuits and tell me of there is anything wrong with it (I already found out that LCD pins 1 & 2 were connected wrong in this schematic)


