due to the limit of space in my upcoming project I need to design a PCB, which is as small as possible.
It just needs to run MB_KB, so the only things, which are necessary, are the power supply (no USB needed here) and power-schematic (not included in the attached image), the LPC itself, the 74HCT541N, MIDI Out 1, J5A (for sustain / expression) and J8/9 (for DIO_Matrix).
So here is my design I just created. I need someone to confirm, that it will work like this and I didn’t forget any connections. For example: How about the unused pins of the 74HCT541N? Do I need to ground them?
I haven’t checked all the connections of your circuit diagram (sorry).
But I did look at your schematic in relation to unused pins on the 74HC541.
The unused pins are outputs and should be left open not grounded.
There a connections to the corresponding input gates from the core. You need to make sure these signals are active (configured as outputs by the firmware) otherwise remove the tracks and connect the inputs to ground (as TK suggested). These tracks (connecting the core to the inputs of unused gates) are not performing any function.
