feat(cdc_acm): Add CDC-ACM support and remove old test applications

- Implemented CDC-ACM (USB Virtual COM Port) support for the slave_node application.
- Removed the now obsolete 'hello_world' and 'stm32g431_tests' applications.

software/apps/hello_world/CMakeLists.txt

@@ -1,6 +0,0 @@
-cmake_minimum_required(VERSION 3.20)
-
-find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
-project(hello_world)
-
-target_sources(app PRIVATE src/main.c)

software/apps/hello_world/prj.conf

@@ -1,4 +0,0 @@
-
-CONFIG_CONSOLE=y
-CONFIG_LOG=y
-CONFIG_UART_CONSOLE=y

software/apps/hello_world/src/main.c

@@ -1,9 +0,0 @@
-#include <zephyr/kernel.h>
-#include <zephyr/sys/printk.h>
-
-int main(void)
-{
-	printk("Hello World! %s\n", CONFIG_BOARD);
-	return 0;
-}
-

software/apps/slave_node/cdc-acm.overlay

@@ -0,0 +1,10 @@
+&zephyr_udc0 {
+	cdc_acm_uart0: cdc_acm_uart0 {
+		compatible = "zephyr,cdc-acm-uart";
+
+		modbus0 {
+			compatible = "zephyr,modbus-serial";
+			status = "okay";
+		};
+	};
+};

software/apps/slave_node/overlay-cdc-acm.conf

@@ -0,0 +1,4 @@
+CONFIG_USB_DEVICE_STACK=y
+CONFIG_USB_DEVICE_PRODUCT="Modbus slave node"
+CONFIG_UART_LINE_CTRL=y
+CONFIG_USB_DEVICE_INITIALIZE_AT_BOOT=n

software/apps/stm32g431_tests/CMakeLists.txt

@@ -1,6 +0,0 @@
-cmake_minimum_required(VERSION 3.20)
-
-find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
-project(stm32g431_tests)
-
-target_sources(app PRIVATE src/main.c)

software/apps/stm32g431_tests/prj.conf

@@ -1,4 +0,0 @@
-
-CONFIG_CONSOLE=y
-CONFIG_LOG=y
-CONFIG_UART_CONSOLE=y

software/apps/stm32g431_tests/src/main.c

@@ -1,9 +0,0 @@
-#include <zephyr/kernel.h>
-#include <zephyr/sys/printk.h>
-
-int main(void)
-{
-	printk("Hello World! %s\n", CONFIG_BOARD);
-	return 0;
-}
-