I soldered the signal wires between the second SMS Paddle Card junction PCB and the Arduino. Four output wires run to the relay module, which switches power from a third SMS Paddle card delivering 48V and 12V power from the 1130.
My initial connections to the Arduino used wires soldered onto header strips but it was too hard to control shorting side to side since the arduino has a double row of sockets. I then picked up a shield that plugs onto the Arduino and provides screw terminals for all the connectors. This gave me a more secure and reliable interconnect.
Given the tight quarters inside the box, I had to do a trial fit of the six PCBs (relay module, two junction boards, display board, BCD/LED converter and Arduino) to select the locations to mount everything. The display board and its converter mount on the inside of the top (face) plate, of course, stacked on standoffs.
|Board stack for 7 segment displays and BCD decoders|
|Boards installed and wired up inside the box|
|Box closed up but not yet labeled|
I will do some cosmetic improvement of the placement of the buttons on the faceplate - widening the hole and gluing them down to make them align better. Labeling of the button functions using my label transfer technology will complete the cosmetics of the unit. This work will occur at a future date.