diff --git a/c-with-rust/CMakeLists.txt b/c-with-rust/CMakeLists.txt
index 39aacea..8881ab8 100644
--- a/c-with-rust/CMakeLists.txt
+++ b/c-with-rust/CMakeLists.txt
@@ -15,11 +15,14 @@ add_executable(
         blink.c
         )
 
+add_subdirectory(rblink)
+add_dependencies(blink rblink)
+
 # pull in common dependencies
 target_link_libraries(
 	blink 
 	pico_stdlib
-	/tmp/cargo-target/thumbv6m-none-eabi/release/librblink.a
+	${CMAKE_CURRENT_BINARY_DIR}/rblink/librblink.a
 	)
 
 # create map/bin/hex file etc.
diff --git a/c-with-rust/blink.c b/c-with-rust/blink.c
index 8bff825..69bc508 100644
--- a/c-with-rust/blink.c
+++ b/c-with-rust/blink.c
@@ -51,6 +51,9 @@ int c_main() {
         gpio_put(LED_PIN, 0);
         sleep_ms(sleep);
         sleep = add_half(sleep);
+        if(sleep > 2000) {
+            reset_usb_boot(LED_PIN, 0);
+        }
     }
 }
 
diff --git a/c-with-rust/build.sh b/c-with-rust/build.sh
index 838e049..9f99bb1 100755
--- a/c-with-rust/build.sh
+++ b/c-with-rust/build.sh
@@ -5,9 +5,6 @@ set -euxo pipefail
 
 SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
 
-cd "$SCRIPT_DIR"/rblink
-CARGO_TARGET_DIR=/tmp/cargo-target cargo build --release --target thumbv6m-none-eabi
-
 mkdir -p /tmp/8
 cd /tmp/8
 
diff --git a/c-with-rust/rblink/CMakeLists.txt b/c-with-rust/rblink/CMakeLists.txt
new file mode 100644
index 0000000..dd10d95
--- /dev/null
+++ b/c-with-rust/rblink/CMakeLists.txt
@@ -0,0 +1,20 @@
+if (CMAKE_BUILD_TYPE STREQUAL "Debug")
+    set(CARGO_CMD cargo build --target thumbv6m-none-eabi)
+    set(TARGET_DIR "debug")
+else ()
+    set(CARGO_CMD cargo build --release --target thumbv6m-none-eabi)
+    set(TARGET_DIR "release")
+endif ()
+
+set(RBLINK_A "${CMAKE_CURRENT_BINARY_DIR}/thumbv6m-none-eabi/${TARGET_DIR}/librblink.a")
+
+add_custom_target(rblink ALL
+    COMMENT "Compiling rblink module"
+    COMMAND CARGO_TARGET_DIR=${CMAKE_CURRENT_BINARY_DIR} ${CARGO_CMD}
+    COMMAND cp ${RBLINK_A} ${CMAKE_CURRENT_BINARY_DIR}
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
+set_target_properties(rblink PROPERTIES LOCATION ${CMAKE_CURRENT_BINARY_DIR})
+
+add_test(NAME rblink_test
+    COMMAND cargo test
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})