Split up code into namespaces.

led_blaster.cpp

@@ -0,0 +1,32 @@
+#define LED_PIN 13
+
+#define LED_ON_MS 35
+#define LED_OFF_MS 460
+
+#include <Arduino.h>
+
+namespace LedBlaster {
+  void setup() {
+    pinMode(LED_PIN, OUTPUT);
+  }
+
+  void emit_0() {
+    digitalWrite(LED_PIN, HIGH);
+    delayMicroseconds(LED_ON_MS);
+
+    digitalWrite(LED_PIN, LOW);
+    delayMicroseconds(LED_OFF_MS);
+  }
+
+  void emit_1() {
+    delayMicroseconds(LED_ON_MS + LED_OFF_MS);
+  }
+
+  void emit_byte(uint8_t serial_byte) {
+    emit_0();
+
+    for (int i = 0; i < 8; i++) {
+      bitRead(serial_byte, i) ? emit_1() : emit_0();
+    }
+  }
+}

led_blaster.h

@@ -0,0 +1,13 @@
+#ifndef LED_BLASTER_H
+#define LED_BLASTER_H
+
+#include <Arduino.h>
+
+namespace LedBlaster {
+  void setup();
+  void emit_0();
+  void emit_1();
+  void emit_byte(uint8_t serial_byte);
+}
+
+#endif

notebook_adapter.cpp

@@ -0,0 +1,55 @@
+#ifndef NOTEBOOK_ADAPTER_H
+#define NOTEBOOK_ADAPTER_H
+
+#define COMMAND_PING 'x'
+#define COMMAND_QUERY '?'
+#define COMMAND_TRANSMIT 'U'
+#define COMMAND_QUERY_PAYLOAD "M764"
+
+#define PING_EXPIRE_MS 1000
+
+#include <Arduino.h>
+
+namespace NotebookAdapter {
+  unsigned long last_ping_ms = 0;
+  bool command_mode = true;
+
+  void emulate_command_mode(uint8_t serial_byte) {
+    switch(serial_byte) {
+      case COMMAND_PING:
+        Serial.write(COMMAND_PING);
+
+        break;
+
+      case COMMAND_QUERY:
+        Serial.print(COMMAND_QUERY_PAYLOAD);
+        Serial.write(0);
+
+        break;
+
+      case COMMAND_TRANSMIT:
+        Serial.write(COMMAND_TRANSMIT);
+        command_mode = false;
+
+        break;
+    }
+  }
+
+  void emulate_data_mode(uint8_t serial_byte) {
+    if (millis() - last_ping_ms > PING_EXPIRE_MS) {
+      command_mode = true;
+    }
+
+    Serial.write(serial_byte);
+
+    last_ping_ms = millis();
+  }
+
+  void emulate(uint8_t serial_byte) {
+    void(*function)(uint8_t) = command_mode ? emulate_command_mode : emulate_data_mode;
+
+    function(serial_byte);
+  }
+}
+
+#endif

notebook_adapter.h

@@ -0,0 +1,12 @@
+#ifndef NOTEBOOK_ADAPTER_H
+#define NOTEBOOK_ADAPTER_H
+
+#include <Arduino.h>
+
+namespace NotebookAdapter {
+  void emulate_command_mode(uint8_t serial_byte);
+  void emulate_data_mode(uint8_t serial_byte);
+  void emulate(uint8_t serial_byte);
+}
+
+#endif

timex-datalink-arduino.ino

@@ -1,87 +1,16 @@
-#define LED_PIN 13
-
-#define LED_ON_MS 35
-#define LED_OFF_MS 460
-
-#define COMMAND_PING 'x'
-#define COMMAND_QUERY '?'
-#define COMMAND_TRANSMIT 'U'
-#define HANDSHAKE_PAYLOAD "M764"
-
-#define PING_EXPIRE_MS 1000
-
-unsigned long last_ping_ms = 0;
-bool command_mode = true;
-
-void led_emit_0() {
-  digitalWrite(LED_PIN, HIGH);
-  delayMicroseconds(LED_ON_MS);
-
-  digitalWrite(LED_PIN, LOW);
-  delayMicroseconds(LED_OFF_MS);
-}
-
-void led_emit_1() {
-  delayMicroseconds(LED_ON_MS + LED_OFF_MS);
-}
-
-void led_emit_byte(uint8_t serial_byte) {
-  led_emit_0();
-
-  for (int i = 0; i < 8; i++) {
-    bitRead(serial_byte, i) ? led_emit_1() : led_emit_0();
-  }
-}
-
-void emulate_notebook_adapter_command(uint8_t serial_byte) {
-  switch(serial_byte) {
-    case COMMAND_PING:
-      Serial.write(COMMAND_PING);
-
-      break;
-
-    case COMMAND_QUERY:
-      Serial.print(HANDSHAKE_PAYLOAD);
-      Serial.write(0);
-
-      break;
-
-    case COMMAND_TRANSMIT:
-      Serial.write(COMMAND_TRANSMIT);
-      command_mode = false;
-
-      break;
-  }
-}
-
-void emulate_notebook_adapter_data(uint8_t serial_byte) {
-  if (millis() - last_ping_ms > PING_EXPIRE_MS) {
-    command_mode = true;
-  }
-
-  Serial.write(serial_byte);
-
-  last_ping_ms = millis();
-}
-
-void emulate_notebook_adapter(uint8_t serial_byte) {
-  void(*function)(uint8_t) = command_mode ? emulate_notebook_adapter_command : emulate_notebook_adapter_data;
-
-  function(serial_byte);
-}
+#include "led_blaster.h"
+#include "notebook_adapter.h"
 
 void setup() {
   Serial.begin(9600);
-  pinMode(LED_PIN, OUTPUT);
+  LedBlaster::setup();
 }
 
 void loop() {
   int serial_byte = Serial.read();
 
-  if (serial_byte == -1) {
-    return;
+  if (serial_byte != -1) {
+    LedBlaster::emit_byte(serial_byte);
+    NotebookAdapter::emulate(serial_byte);
   }
-
-  led_emit_byte(serial_byte);
-  emulate_notebook_adapter(serial_byte);
 }