Modifications to Motherboard

Schematic changes

• Add 8th SA board slot

• Currently M1 is different from all the others in that it has only a PWM board. Add an ADC board (maybe call it M1a) and wire it just like the other pairs (M2, M3) (M4, M5) etc.

• Expand ribbon cable headers P1...P16 from 14 to 16 pins with extra pair connected to M1a. Check with Brandon about pinout

• Also, Move ribbon cable headers to back of board.

Change power input scheme

• Currently there is one power input per mezzanine board via P31. Change this so that there are two high-current inputs (+5V and +24V). Each mezzanine site would have a two-position plug jumper to select the voltage it receives.
  • e.g Jumper plug DigiKey?# 952-2749-ND with sockets ED5019-ND (3 used)

• Input may be on mini-fit connector as now or possibly a PCB mount terminal strip with screw terminals.

• Add 4x micro-USB connectors with only GND, 5V connected to power Raspberry Pi and other things (check with Brandon for position on board)

• Add address resistors to board for each Arduino (talk to Zach)

• Replace DE-9 connector pair J2 with dual RJ-11 (sic. actually RJ14) connector
  • Use 6p4c type (4 middle pins of 6 populated) e.g. DigiKey? WM9177-ND

Layout Changes

(All changes required by schematic updates) plus:

Expand board outline to about 12.6 x 14.5 inches.

Move P1...P16 to back and place in array according to top plate drawing.

Place new connectors (USB) as specified by Brandon