diff --git a/arduino/msaqsg/ch04/Telegraph/Makefile b/arduino/msaqsg/ch04/Telegraph/Makefile
new file mode 120000
index 0000000..bf3dbf5
--- /dev/null
+++ b/arduino/msaqsg/ch04/Telegraph/Makefile
@@ -0,0 +1 @@
+../../../arduino.mk
\ No newline at end of file
diff --git a/arduino/msaqsg/ch04/Telegraph/Telegraph.ino b/arduino/msaqsg/ch04/Telegraph/Telegraph.ino
new file mode 100644
index 0000000..6133ba2
--- /dev/null
+++ b/arduino/msaqsg/ch04/Telegraph/Telegraph.ino
@@ -0,0 +1,5 @@
+void setup() {
+}
+
+void loop() {
+}
diff --git a/arduino/msaqsg/ch04/Telegraph/telegraph.cpp b/arduino/msaqsg/ch04/Telegraph/telegraph.cpp
new file mode 100644
index 0000000..a5fd161
--- /dev/null
+++ b/arduino/msaqsg/ch04/Telegraph/telegraph.cpp
@@ -0,0 +1,46 @@
+// vim:filetype=arduino
+#include <ctype.h>
+#include <Arduino.h>
+#include "telegraph.h"
+
+const char* LETTERS[] = {
+    ".-",   // A
+    "-...", // B
+    "-.-.", // C
+    "-..",  // D
+    ".",    // E
+    "..-.", // F
+    "--.",  // G
+    "....", // H
+    "..",   // I
+    ".---", // J
+    "-.-",  // K
+    ".-..", // L
+    "--",   // M
+    "-.",   // N
+    "---",  // O
+    ".--.", // P
+    "--.-", // Q
+    ".-.",  // R
+    "...",  // S
+    "-",    // T
+    "..-",  // U
+    "...-", // V
+    ".--",  // W
+    "-..-", // X
+    "-.--", // Y
+    "--.."  // Z
+};
+
+const char* DIGITS[] = {
+    "-----", // 0
+    ".----", // 1
+    "..---", // 2
+    "...--", // 3
+    "....-", // 4
+    ".....", // 5
+    "-....", // 6
+    "--...", // 7
+    "---..", // 8
+    "----.", // 9
+};
diff --git a/arduino/msaqsg/ch04/Telegraph/telegraph.h b/arduino/msaqsg/ch04/Telegraph/telegraph.h
new file mode 100644
index 0000000..437d99d
--- /dev/null
+++ b/arduino/msaqsg/ch04/Telegraph/telegraph.h
@@ -0,0 +1,18 @@
+#ifndef __TELEGRAPH_H__
+#define __TELEGRAPH_H__
+
+class Telegraph {
+public:
+    Telegraph(const int output_pin, const int dit_length);
+    void send_message(const char* message);
+private:
+    void dit();
+    void dah();
+    void output_code(const char* code);
+    void output_symbol(const int length);
+
+    int _output_pin;
+    int _dit_length;
+    int _dah_length;
+};
+#endif