User Interface: Display A Initial Design and Construction
As with the data switches I knew all along what type/style of components I wanted to use to act as a display and switch over a single control line ... in this case I've specifically gone for the NKK JB series which are illuminated tactile switches. These are momentary switches and available in either red, green or yellow (I'll use all three colours in the final display). The switches are X/Y stackable so it's quite easy to make keypad type layouts with them. Internally the switches are laid out like this:
With the switches selected and a method of labelling them tried and tested it was time to design the display board itself. As with the switch control board shown in the last post this board has gaps in it where more functionality will be added later on. This is the design so far with key caps on:
As always these schematics are available on my Google Docs here for the schematic with switches and here without the switches.
So, with the design ready to go I could get out the soldering iron and get stuck in. The only real change from previous cards is that all the wiring is done on the back side of the card this time with soldered Kynar wire. Other than that there's nothing too surprising or unusual in the construction so I'll get straight on with the pictures. Here is the card as it currently stands viewed from the front: