This is just some additional info, so that you can understand exactly what i am trying to do:
Sorry just noticed i dont have any values in for C3/C4, but yes they are a ceramic and eletrolytic cap in parallell and close to the supply pins for the IC's.
The connector marked 'Input' J1 is connected to 12v ign wire, vehicle gnd, a tacho wire (on some cars a replacemnt or additional sensor may be required), a speed sensor wire, as before additional sensor may be required.
The speed and revs signal can be either 12v or 5v depending on the settings of dip switch 1 and 2 (which bypass the potential divider if 5v signals are used)
J2 'Control' is a ALPS incremental encoder with switch
J3 'LCD' is the lcd (the control is used to navigate menu's on here)
J4 'Shift' this is a row of leds, although only the first 5 are used (future proofing - connect all 8)
j5 'Speed' this is a set of 3 '7 seg' displays reasonably big ones, the ones i use just now are about 2 inch tall
j6 'Revs' this is a row of leds for display of revs (Very configurable - either one LOOOOONG line , or as i use them just now , 16 Bi-Colour leds, so that as you approch the rev limit they change color)
I also attached some pictures of what i have done on breadboard, but the aim here is to make a pcb, and i cannot afford to make a mistake.
I am no longer aiming for one big board like in my picture, but rather a small universal board about 2"x2", with everything connecting via cables. (the last pic is where i got to before starting this thread)
Thanks, and as always any other comments welcome.
PS, where is the most likely source of noise on my PCB, is there any components that need to be kept far away from each other.
The display driver (7219) refreshes at 800Hz if that makes any difference.