Added more to QMK guide

qmk-guide/README.md

@@ -121,7 +121,7 @@ The columns need to be wired with diodes. You can probably wire the entire
 column with the diode stems, but I chose to add some wire segments so it would
 look clearer for this guide.
 
-![](dactyl-left-wiring.jpg)
+![](dactyl-right-wiring.jpg)
 
 The diodes need the black bar facing away from the key. The other guides
 disagree, but they don't use QMK.
@@ -240,6 +240,95 @@ run GND to the fourth terminal.
 
 ![](trrs-diagram.jpg)
 
+### LEDs
+
+We talked about choosing them before, but here's how to wire them. You can make
+them all do what you want in your QMK keymap at will.
+
+I put them in the top rightmost MX switches, but I'd love to find a place to
+incorporate them directly in the case.
+
+Here's what that looked like:
+![](dactyl-bare-led.jpg)
+
+And with a cap:
+![](dactyl-capped-led.jpg)
+
+I did my best here to try and isolate the Green, Brown and Blue wires heading
+from the Teensy to each LED, the 220Ω resistors and the Black wire to the Ground
+terminal via the TRRS pin.
+
+| LED | Wire Color | Teensy Pin |
+|-----|------------|------------|
+| 1   | Green      | PB5        |
+| 2   | Brown      | PB6        |
+| 3   | Blue       | PB7        |
+
+![](dactyl-led-wiring.jpg)
+
 ## Wiring The Left Half
 
-### Wiring the I/O Expander
+I wired the left half to be a mirror image of the right, with the mirror between
+the two halves. That means the rows are the same, but the column are both purple
+on the outside, and red on the inside.
+
+Here's the color coding and pin outs for the left half:
+
+| Row     | Wire Color | MCP23018 Pin |
+|---------|------------|--------------|
+| 0       | Yellow     | GPB0         |
+| 1       | Orange     | GPB1         |
+| 2       | Green      | GPB2         |
+| 3       | Brown      | GPB3         |
+| 4       | Blue       | GPB4         |
+| 5       | Purple     | GPB5         |
+
+| Column | Wire Color | Teensy Pin |
+|--------|------------|------------|
+| 0      | Purple     | GPA6       |
+| 1      | Blue       | GPA5       |
+| 2      | Brown      | GPA4       |
+| 3      | Green      | GPA3       |
+| 4      | Orange     | GPA2       |
+| 5      | Yellow     | GPA1       |
+| 6      | Red        | GPA0       |
+
+And here's the left half wired up:
+
+![](dactyl-left-wiring.jpg)
+
+The rules are pretty much the same as the right half. Black bar on the diode
+facing away from the switch.
+
+### Connecting to the MCP23018
+
+I am really too entertained that the company that makes this microchip is called
+Microchip, which got me into the habit of calling the MCP "microchip by
+Microchip". The big takeaway here is that it's a microchip, and not a cool dev
+board like the Teensy. What this means for you is soldering a bunch of terribly
+tiny wires to terribly tiny pins.
+
+Hand wiring microchip is incredibly frustrating. I broke a pin off my first one,
+pretty much rendering it useless. Fortunately, there's an easier way.
+
+I still wound up soldering the connections from the TRRS jack to the MCP. There
+were also some pins that I connected with short wires.
+
+* Vss -> ADDR -> TRRS
+* RESET -> Vdd -> TRRS
+* SCL -> TRRS
+* SDA -> TRRS
+
+All that's left are the rows and columns. I trimmed a 28pin IC socket down to a
+7pin and 6pin single row socket, and soldered the matrix to those. Then I was
+able to clip them on to the right spots on the MCP.ß
+
+Here the colums clip right on:
+![](dactyl-mcp-ic-socket.jpg)
+
+And the rows too: I know I labeled the rows incorrectly, I was working off the
+old guide which numbers rows differently.
+
+![](dactyl-mcp-ic-socket2.jpg)
+
+The left side requires more precise work, but it's a simpler wiring job.