A simple and practical board for 14-Segments LED Displays with 8 14mm digits and 3 3mm signalation LEDs. The main feature of this board is the need of as low as two digital lines to be driven.
Through the employ of a M5451, which is capable to warrant the correct driving fo each segment, the circuitry is reduced to the minimum complexity making this solution suitable for efficent use in all the applications that need to make LED display signalations.
Software management plays an important role, like hardware. The reported program example has been built through the powerful and inexpansive BASCOM Compiler (LT; 8051; AVR) and C Compiler (µC/51); not for this cause the program couldn't have been built using a different language or for any other CPU.
To work properly, only 2 I/O signals and an Interrupt Routine are needed. The program has been designed to be used very easily in conjunction with other programs and, at the same time, to be helpful in understanding the 14-Segments display multiplexing management.
C1 = 22µF 6v Tantalio
C2 = 1nF 50v poliester
C3, C4 = 100nF Multilayer
R1, R2, R3 , R4, R5, R6 , R7 = 4k7 Ohm 1/4w
LD1, LD2, LD3, LD4 = LED 3mm Red
DY1 = PDA54-11 display 14 segment *2
DY2 = PDA54-11 display 14 segment *2
DY3 = PDA54-11 display 14 segment *2
DY4 = PDA54-11 display 14 segment *2
IC1 = M5451
IC2 = ULN2074
CN1 = 4 way screw, 2,54mm
40 pin sockets
16 pin sockets