diff --git a/tools/changing-of-the-guard.cpp b/tools/changing-of-the-guard.cpp
new file mode 100644
index 0000000..ce279cd
--- /dev/null
+++ b/tools/changing-of-the-guard.cpp
@@ -0,0 +1,73 @@
+//changing of the guard - made for @hyperiondev's microcontrollers
+#include <iostream>
+#include <fstream>
+#include <string>
+#include <algorithm>
+
+std::string convert(std::string str) {
+	str = str.substr(str.find_last_of("\\/")+1);
+	std::transform(str.begin(), str.end(), str.begin(), ::toupper);
+	std::replace(str.begin(), str.end(), '.', '_');
+	return str;
+}
+
+std::string convertToGuardStart(std::string str) {
+	str = convert(str);
+	return "#ifndef " + str + "\n#define " + str + "\n";
+}
+
+std::string convertToGuardEnd(std::string str) {
+	str = convert(str);
+	return "\n#endif //" + str + "\n";
+}
+
+int main(int argc, char** argv) {
+	if (argc <= 1) {
+		return -1;
+	}
+
+	for (int fileCounter = 1; fileCounter < argc; fileCounter++) {
+		std::ifstream is; //input stream
+		std::string buffer; //store output file
+
+		//open
+		is.open(argv[fileCounter]);
+		if (!is.is_open()) {
+			return -1;
+		}
+
+		while (!is.eof()) {
+			std::string top; //I dislike C++
+			getline(is, top);
+
+			//check for pragma guard
+			if (top == "#pragma once") {
+				top = convertToGuardStart(argv[fileCounter]);
+				getline(is, buffer, '\0');
+				buffer += convertToGuardEnd(argv[fileCounter]);
+			}
+			else {
+				top += "\n";
+				getline(is, buffer, '\0');
+			}
+
+			buffer = top + buffer;
+		}
+
+		//finally
+		is.close();
+
+		std::ofstream os;
+
+		os.open(argv[fileCounter]);
+		if (!os.is_open()) {
+			return -1;
+		}
+
+		os << buffer;
+
+		os.close();
+	}
+
+	return 0;
+}