Merge pull request #761 from kripton/kripton-rp2xxx

Minor changes in the rp2xx howto document

docs/pico_sdk.md

@@ -6,19 +6,22 @@ Follow the Raspberry Pi Foundation's
 setup a proper development environment on your host PC (the machine that
 will build your project).
 
-It is important to remember that the pico-sdk repository should exist in the same directory that the RF24 repository (or your project's directory) exists.
+Either set an environment variable named `PICO_SDK_PATH` that points to your
+local clone of the pico-sdk or put the pico-sdk next to the `RF24` folder or
+the folder containing your project using the `RF24` library:
 
  path/to/github/repos/
   pico-sdk/
   RF24/
 
 Alternatively, the RF24 repository (and optionally the RF24Network and RF24Mesh
 repositories) can be included into your project's "lib" folder as copies or
-git submodules. for more detail, see the below instructions to incorporate RF24 libs into your project.
+git submodules. For more detail, see the below instructions to incorporate
+RF24 libs into your project.
 
 ## Building the RF24 examples for the Pico SDK
-1. Create a "build" directory in the RF24 repository's root directory, then navigate to
- the new "build" directory.
+1. Create a "build" directory in the RF24 repository's root directory and
+ navigate to it:
  ```shell
  cd RF24
  mkdir build
@@ -72,12 +75,19 @@ In order to use the RF24 libraries in your RP2040 based project:
  include(../lib/RF24Mesh/CMakeLists.txt)
  ```
 3. In the same CMakeLists.txt file from step 2, add the RF24 libraries into the
- `target_link_libraries` configuration.
+ `target_link_libraries` configuration:
  ```txt
- target_include_directories(target_name PRIVATE ${CMAKE_CURRENT_LIST_DIR})
+ target_link_libraries(${CMAKE_PROJECT_NAME}
+ # ... Your project's other libraries ...
+ RF24
+ RF24Network
+ RF24Mesh
+ )
+ ```
+ If you are using tinyUSB, this line (or similar) should already exist:
+ ```txt
+ target_include_directories(${CMAKE_PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_LIST_DIR})
  ```
- Where `target_name` is specified prior to this call using
- [`add_executable()`](https://cmake.org/cmake/help/latest/command/add_executable.html#command:add_executable)
 4. Finally, remember to include the necessary RF24* libraries' header files in your
  project's source code where applicable.
  ```cpp
@@ -125,7 +135,7 @@ void main()
 To specify the default SPI pins used at build time, you can use either:
 1. declare these pins in the CMakeLists.txt file
  ```txt
- target_compile_definitions(target_name
+ target_compile_definitions(${CMAKE_PROJECT_NAME}
  PUBLIC PICO_DEFAULT_SPI=0 # can only be 0 or 1 (as in `spi0` or `spi1`)
  PUBLIC PICO_DEFAULT_SPI_SCK_PIN=2 # depends on which SPI bus (0 or 1) is being used
  PUBLIC PICO_DEFAULT_SPI_TX_PIN=3 # depends on which SPI bus (0 or 1) is being used