docs: Revise "Troubleshooting" for Zephyr 3.0 (#1214)

Co-authored-by: Cem Aksoylar <caksoylar@users.noreply.github.com>
Co-authored-by: Dom H <dom@hxy.io>

docs/docs/behaviors/key-press.md

@@ -33,11 +33,6 @@ provided by ZMK near the top:
 
 Doing so makes a set of defines such as `A`, `N1`, etc. available for use with these behaviors
 
-### Improperly defined keymap - `dtlib.DTError: <board>.dts.pre.tmp:<line number>`
-
-When compiling firmware from a keymap, it may be common to encounter an error in the form of a`dtlib.DTError: <board>.dts.pre.tmp:<line number>`.
-For instructions to resolve such an error, click [here](../troubleshooting.md###Improperly-defined-keymap)
-
 ## Key Press
 
 The "key press" behavior sends standard keycodes on press/release.

docs/docs/troubleshooting.md

@@ -26,28 +26,35 @@ Variations of the warnings shown below occur when flashing the `<firmware>.uf2`
 An error along the lines of `CMake Error at (zmk directory)/zephyr/cmake/generic_toolchain.cmake:64 (include): include could not find load file:` during firmware compilation indicates that the Zephyr Environment Variables are not properly defined.
 For more information, click [here](../docs/development/setup.md#environment-variables).
 
-### dtlib.DTError
+### West Build Errors
 
-An error along the lines of `dtlib.DTError: <board>.dts.pre.tmp:<line number>` during firmware compilation indicates an issue within the `<shield>.keymap` file.
+West build errors usually indicate syntax problems in the `<keyboard>.keymap` file during the compilation process. The following are some examples and root causes.
-This can be verified by checking the file in question, found in `mkdir/app/build`.
-
-|                  ![Example Error Screen](../docs/assets/troubleshooting/keymaps/errorscreen.png)                   |
-| :----------------------------------------------------------------------------------------------------------------: |
-| An example of the dtlib.DTError when compiling an iris with the nice!nano while the keymap is not properly defined |
-
-After opening the `<board>.dts.pre.tmp:<line number>` and scrolling down to the referenced line, one can locate errors within their shield's keymap by checking if the referenced keycodes were properly converted into the correct [USB HID Usage ID](https://www.usb.org/document-library/hid-usage-tables-12).
 
 :::note
-If you are reviewing these errors in the GitHub Actions tab, the contents of `<board>.dts.pre.tmp` is output (with line numbers) in the next step of the build process.
+If you are reviewing these errors in the GitHub Actions tab, they can be found in the `West Build` step of the build process.
 :::
 
-|                                                                   ![Unhealthy Keymap Temp](../docs/assets/troubleshooting/keymaps/unhealthyEDIT.png)                                                                   |
+#### devicetree error
-| :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------: |
-| An incorrectly defined keymap unable to compile. As shown in red, `&kp SPAC` is not a valid reference to the [USB HID Usage ID](https://www.usb.org/document-library/hid-usage-tables-12) used for "Keyboard Spacebar" |
 
-|                                                                               ![Healthy Keymap Temp](../docs/assets/troubleshooting/keymaps/healthyEDIT.png)                                                                               |
+A `devicetree error` followed by a reference to the line number on `<keyboard>.keymap` refers to an issue at the exact line position in that file. For example, below error message indicates a missing `;` at line 109 of the `cradio.keymap` file:
-| :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------: |
+
-| A properly defined keymap with successful compilation. As shown in red, the corrected keycode (`&kp SPACE`) references the proper Usage ID defined in the [USB HID Usage Tables](https://www.usb.org/document-library/hid-usage-tables-12) |
+```
+devicetree error: /__w/zmk-config/zmk-config/config/cradio.keymap:109 (column 4): parse error: expected ';' or ','
+```
+
+#### devicetree_unfixed.h error
+
+A `devicetree_unfixed.h` error that follows with an "undeclared here" string indicates a problem with key bindings, like behavior nodes (e.g. `&kp` or `&mt`) with incorrect number of parameters:
+
+```
+/__w/zmk-config/zmk-config/build/zephyr/include/generated/devicetree_unfixed.h:3756:145: error: 'DT_N_S_keymap_S_symbol_layer_P_bindings_IDX_12_PH_P_label' undeclared here (not in a function); did you mean 'DT_N_S_keymap_S_symbol_layer_P_bindings_IDX_16_PH'?
+```
+
+In this example, the error string `DT_N_S_keymap_S_symbol_layer_P_bindings_IDX_12_PH_P_label` indicates a problem with the key binding in position `12` in the `symbol_layer` of the keymap.
+
+:::note
+Key positions are numbered starting from `0` at the top left key on the keymap, incrementing horizontally, row by row.
+:::
 
 ### Split Keyboard Halves Unable to Pair