changed eigen dependency to be fetch content so it is more platform independent

Author: JMoore5353

.github/workflows/varmint_firmware.yml

@@ -12,7 +12,7 @@ jobs:
     - name: checkout submodules
       run: git submodule update --init --recursive
     - name: install toolchain
-      run: sudo apt -y install gcc-arm-none-eabi libeigen3-dev
+      run: sudo apt -y install gcc-arm-none-eabi
     - name: check toolchain
       run: arm-none-eabi-gcc --version
     - name: build varmint

CMakeLists.txt

@@ -28,18 +28,24 @@ if("${GIT_VERSION_HASH}" STREQUAL "")
   set(GIT_VERSION_HASH "0")
 endif()
 
-### source files ###
-find_package(Eigen3 REQUIRED)
-include_directories(${EIGEN3_INCLUDE_DIRS})
+### Install Eigen dependency ###
+include(FetchContent)
+FetchContent_Declare(
+  Eigen3
+  GIT_REPOSITORY https://gitlab.com/libeigen/eigen.git
+  GIT_TAG origin/3.4
+)
+FetchContent_MakeAvaliable(Eigen3)
 
+### source files ###
 include_directories(
     include
     include/interface
     lib
     comms/mavlink
     comms/mavlink/v1.0
     comms/mavlink/v1.0/common
-    comms/mavlink/v1.0/rosflight
+    ${eigen3_SOURCE_DIR}
 )
 
 file(GLOB_RECURSE ROSFLIGHT_SOURCES