erice1984, few comments on your last schematic.

a) NPN transistors are wrongly used (emitter should be grounded).

b) PNP should have a base pullup resistor (4,7K will work).

c) Diode D2 should be placed across emitter and collector of T4 to be of any use.

d) Connector SL1 has two wires missing, since you will need ground and Vdd


Al.