I'm developing a car parking sensor with two HC-SR04, an LCD, buzzer and LED blinking at 500ms.
I finish the project yesterday and everything works fine. Today i try to change a line of code and nathing works and i get back to original code and still unworking.
If i connect the VCC and VSS of LCD on board the program doesnt work but if i put just the VDD the sonar works and the buzzer blink like i want, but the screen doesnt show information and LED blink but almost dont see it.
Anyone know what happen?, its really strange because yeserday all works together and i didnt modify the circuit.