added test macro in readme

.devcontainer/Dockerfile

@@ -0,0 +1,24 @@
+# Use Ubuntu as the base image
+FROM ubuntu:latest
+
+# Update and install necessary dependencies
+RUN apt-get update && apt-get install -y \
+    build-essential \
+    curl \
+    git \
+    vim \
+    avr-libc gcc-avr binutils-avr \
+    avrdude \
+    && rm -rf /var/lib/apt/lists/*
+
+# Set the working directory to /workspace (VSCode will mount your local folder here)
+WORKDIR /workspace
+
+# Set the default user as root for installing packages
+USER root
+
+# Expose any necessary ports (if needed)
+# EXPOSE 3000
+
+# Run bash as the default command when the container starts
+CMD ["/bin/bash"]

.devcontainer/devcontainer.json

@@ -0,0 +1,11 @@
+{
+  "name": "Ubuntu DevContainer",
+  "dockerFile": "Dockerfile", // Reference to your Dockerfile
+  "context": ".", // The context is the root of your project
+  "workspaceFolder": "/workspace", // Where VSCode will mount your current folder inside the container
+  "mounts": [
+    "source=${localWorkspaceFolder},target=/workspace,type=bind",
+    "source=/dev/tty.usbserial-310,target=/dev/ttyUSB0,type=bind"
+  ],
+  "postCreateCommand": "echo 'Devcontainer setup complete!'"
+}

README.md

@@ -79,3 +79,38 @@ avrdude: safemode: Fuses OK (E:00, H:00, L:00)
 
 avrdude done.  Thank you.
 ```
+
+## test macros
+
+#include <stdio.h>
+#include <avr/io.h>
+
+// // stringify
+#define STRINGIFY_HELPER(x) #x
+#define STRINGIFY(x) STRINGIFY_HELPER(x)
+
+#define CONCAT_HELPER(x, y) x ## y
+#define CONCAT(x, y) CONCAT_HELPER(x, y)
+
+// get argument at nth position
+#define ARG_1(v1, v2) v1
+#define ARG_2(v1, v2) v2
+#define GET_PORT(args) ARG_1 args
+#define GET_BIT(args) ARG_2 args
+
+// actions on registers
+#define SET(register, bit) register |= 1 << bit
+
+// actions on ports
+#define MODE_OUTPUT(elem) SET(CONCAT(DDR, GET_PORT(elem)), GET_BIT(elem))
+
+// elements
+#define LED1 (B, 0)
+
+int main()
+{
+MODE_OUTPUT(LED1);
+
+    return 0;
+
+}