Power Distribution and Communications Board v1.3

Power and Communications Board v1.3

Changes from v1.2.1

Schematic

DONE

• Add debug LED's to TTL Tx/Rx lines (nophead)
• Add debug LED's to RS232 Tx/Rx lines (nophead)
• Add extra capacitor to filter out high frequency noise as per data sheet (nophead)
• Figure out bug with 78L05 and cvpcb failing. (Zach Smith)
• Change power connector to 12v/G alternating connectors. (Zach Smith)
• Swap 4700uF capacitor for two 2200uF capacitors (Simon McAuliffe)
• C7 needs to become a 0.1uF (d0ubled)
• C9 next to c8 and c6 as a 0.1uF (d0ubled)

PCB Layout

DONE

• I would have placed C7 above the regulator to get the track to pin 1 as short as possible. You could then move R2 to where C7 was.
• Move RS232 led's closer to control lines
• Move tx/rx led's to each side of their respective connections.
• Insert new capacitor near 5v regulator
• give the .100 connectors a proper silkscreen for Tx/Rx as well as power.
• Fastener holes: ensure clearance fit for 1/8" (3.125mm) diameter shank (Imperial equivalent of M3). Dia 3.5mm should do it.
• Fastener washer space: ensure circuits avoid the radius of an M3 washer on the fastener holes (metal washers might short the circuit).
• The C6/C8 capacitors are to spec as per the Mouser datasheet.
• Move 1uf capacitor closer to MAX232
• Make .100" holes slightly bigger
• Make make molex holes to spec.
• Double check silkscreens
• The pitch for the resistors looks too small. I would use 0.4". The picture of the 1.2 board on the wiki shows the only resistor half in the air because it does not fit the 0.3" footprint properly.