cuber18
Advanced Member level 4
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i have my led matrix desing in proteus isis.. 7 rows and 40 columns.. i have 74hh154 in my rows and 74hc595 with my columns.. i completed and function it properly.. it is scrolling.. then i attach 7 TIP147 in my rows for current issues.. i connect the TIP147( which is PNP) emitter to VCC then simulated it.. no scrolling is done.. then i tested a single 5x7 led matrix, connecting one of the 7pins to VCC and one of the 5 pins to gnd.. there is no input.. i was confused because i thought my design rows is positive and my columns are negative.. because in my simulation the row pins are red in color which is positive and 40columns are blue which is negative.. so how do i implement it in actual? which is which?
rows = anode and columns = cathode
or
rows = cathode and columns = anode?
rows = anode and columns = cathode
or
rows = cathode and columns = anode?