diff --git a/tools.c b/tools.c
new file mode 100644
index 00000000000..2b452b55b16
--- /dev/null
+++ b/tools.c
@@ -0,0 +1,56 @@
+//
+// Tools for USB HID Autofire
+//
+
+void strrev(char* arr, int start, int end) {
+    char temp;
+
+    if (start >= end)
+        return;
+
+    temp = *(arr + start);
+    *(arr + start) = *(arr + end);
+    *(arr + end) = temp;
+
+    start++;
+    end--;
+    strrev(arr, start, end);
+}
+
+char *itoa(int number, char *arr, int base)
+{
+    int i = 0, r, negative = 0;
+
+    if (number == 0)
+    {
+        arr[i] = '0';
+        arr[i + 1] = '\0';
+        return arr;
+    }
+
+    if (number < 0 && base == 10)
+    {
+        number *= -1;
+        negative = 1;
+    }
+
+    while (number != 0)
+    {
+        r = number % base;
+        arr[i] = (r > 9) ? (r - 10) + 'a' : r + '0';
+        i++;
+        number /= base;
+    }
+
+    if (negative)
+    {
+        arr[i] = '-';
+        i++;
+    }
+
+    strrev(arr, 0, i - 1);
+
+    arr[i] = '\0';
+
+    return arr;
+}
diff --git a/tools.h b/tools.h
new file mode 100644
index 00000000000..9c71ea6ca73
--- /dev/null
+++ b/tools.h
@@ -0,0 +1,7 @@
+#ifndef FLIPPERZERO_FIRMWARE_TOOLS_H
+#define FLIPPERZERO_FIRMWARE_TOOLS_H
+
+void strrev(char *arr, int start, int end);
+char *itoa(int number, char *arr, int base);
+
+#endif //FLIPPERZERO_FIRMWARE_TOOLS_H
diff --git a/usb_hid_autofire.c b/usb_hid_autofire.c
index 9d0bb0c78aa..1333ba94ab4 100644
--- a/usb_hid_autofire.c
+++ b/usb_hid_autofire.c
@@ -4,6 +4,7 @@
 #include <gui/gui.h>
 #include <input/input.h>
 #include "version.h"
+#include "tools.h"
 
 // Uncomment to be able to make a screenshot
 //#define USB_HID_AUTOFIRE_SCREENSHOT
@@ -25,7 +26,9 @@ uint32_t autofire_delay = 10;
 static void usb_hid_autofire_render_callback(Canvas* canvas, void* ctx) {
     UNUSED(ctx);
     char autofire_delay_str[12];
+    //std::string pi = "pi is " + std::to_string(3.1415926);
     itoa(autofire_delay, autofire_delay_str, 10);
+    //sprintf(autofire_delay_str, "%lu", autofire_delay);
 
     canvas_clear(canvas);