- Added a 6+1 pin header to the keypad instead of running it to the push-terminals. The 7th pin (the red line of the ribbon cable) is ground to the keypad.
- Added a JST and +5v wiring to the power supply. The JST is surface mount so it'll be a kludge getting it on the main logic board. The +5v is for the motor driver board.
- Added the cabling for the auto/manual switch and LED. This needs a bit of explanation, so here goes:
- The intention is to pull the auto/man pin assigned on the MCP23017 to ground if set to manual. (switch closed). Ground to the switch centre pin, and return to the MCP GPIO pin.
- This should also light the LED, so this is also the LED cathode, allowing ~18mA to flow.
- In the switch open position the LED has +5v to it's far side, (and flows thru a ~150Ω resistor), but no substantial ground path for any current flow (and the MCP has pull-ups set).
- The voltage at the MCP pin should be ~3v, so essentially this is in a pull-up condition to stop the MCP GPIO pin from floating and giving stray logic-low readings. In the event the MCP isn't configured with pull-ups, this is still (just)within the per-pin tolerance of the MCP to sink up to 20mA.