Apply suggestions from code review

Co-authored-by: Nick Brassel <nick@tzarc.org>

keyboards/ploopyco/trackball_thumb/readme.md

@@ -31,9 +31,9 @@ This should allow you to more heavily customize the behavior.
 
 Alternatively, the `process_wheel` and `process_mouse` functions can both be replaced too, to allow for even more functionality.
 
-Additionally, you can change the DPI/CPI or speed of the trackball by calling `pmw_set_cpi` at any time. Additionally, there is a `DPI_CONFIG` macro that will cycle through an array of options for the DPI.  This is set to 1200, 1600, and 2400, but can be changed.  1600 is also set to the default.
+Additionally, you can change the DPI/CPI or speed of the trackball by calling `pmw_set_cpi` at any time. Additionally, there is a `DPI_CONFIG` keycode that will cycle through an array of options for the DPI.  This is set to 1200, 1600, and 2400, but can be changed.  1600 is also set to the default.
 
-To configure/set your own array, there are two defines to use, `PLOOPY_DPI_OPTIONS` to set the array, and `PLOOPY_DPI_DEFAULT`. 
+To configure/set your own array, there are two defines to use, `PLOOPY_DPI_OPTIONS` to set the array, and `PLOOPY_DPI_DEFAULT`, which is the `0`-based index into the `PLOOPY_DPI_OPTIONS` array. 
 
 ```c
 #define PLOOPY_DPI_OPTIONS { 1200, 1600, 2400 }
@@ -41,11 +41,11 @@ To configure/set your own array, there are two defines to use, `PLOOPY_DPI_OPTIO
 ```
 The `PLOOPY_DPI_OPTIONS` array sets the values that you want to be able to cycle through, and the order they are in.  The "default" define lets the firmware know which of these options is the default and should be loaded by default. 
 
-The `DPI_CONFIG` macro will cycle through the values in the array, each time you hit it.  And it stores this value in persistent memory, so it will load it the next time the device powers up. 
+When inserted into your keymap, the `DPI_CONFIG` keycode will cycle through the values in the array each time you hit it.  It stores this value in persistent memory, so it will remember your selection the next time the device powers up. 
 
 ## Drag Scroll
 
-Drag Sroll is a custom keycode for the Ploopy devices that allow you to hold or tap a button and have the mouse movement translate into scrolling instead. 
+Drag Scroll is a custom keycode for the Ploopy devices that allow you to hold or tap a button and have the mouse movement translate into scrolling instead. 
 
 Nothing needs to be enabled to use this functionality.  Just add the `DRAG_SCROLL` to your keymap. 
 

keyboards/ploopyco/trackball_thumb/rev1_001/config.h

@@ -20,13 +20,6 @@
 
 /*
  * Keyboard Matrix Assignments
- *
- * Change this to how you wired your keyboard
- * COLS: AVR pins used for columns, left to right
- * ROWS: AVR pins used for rows, top to bottom
- * DIODE_DIRECTION: COL2ROW = COL = Anode (+), ROW = Cathode (-, marked on diode)
- *                  ROW2COL = ROW = Anode (+), COL = Cathode (-, marked on diode)
- *
  */
 #define DIRECT_PINS            \
     {                          \

keyboards/ploopyco/trackball_thumb/trackball_thumb.h

@@ -43,6 +43,7 @@ typedef union {
         uint8_t dpi_config;
     };
 } keyboard_config_t;
+_Static_assert(sizeof(keyboard_config_t) == sizeof(uint32_t), "keyboard_config_t size mismatch compared to EEPROM area");
 
 extern keyboard_config_t keyboard_config;
 extern uint16_t          dpi_array[];