diff --git a/keywords.txt b/keywords.txt
index 4117a78..4750cb6 100644
--- a/keywords.txt
+++ b/keywords.txt
@@ -3,8 +3,8 @@ Controller KEYWORD1
 Device KEYWORD1
 VoltageSensor KEYWORD1
 WheelSpeedSensor KEYWORD1
+Peer KEYWORD1
 pulseTriggered KEYWORD2
-equivalent KEYWORD2
 returnFloat KEYWORD2
 returnDouble KEYWORD2
 LEFT_FRONT_WHEEL_SPEED_SENSOR LITERAL1
diff --git a/src/ArrayList.h b/src/ArrayList.h
index 6fdc294..473e7c2 100644
--- a/src/ArrayList.h
+++ b/src/ArrayList.h
@@ -39,46 +39,64 @@ class ArrayList {
     ~ArrayList() { delete[] _array; }
     int size() { return _size; }
     E const *toArray() { return _array; }
-    void set(int index, E element) { _array[index] = element; }
+    void set(int index, const E &element) { _array[index] = element; }
     E get(int index) { return _array[index]; }
     void clear() {
         delete[] _array;
         _array = new E[0];
         _size = _capacity = 0;
     }
-    void add(E element) {
+    void add(const E &element) {
         ensureCapacityInternal(_size + 1);
         _array[_size++] = element;
     }
     ArrayList<E> add(const ArrayList<E> &other) {
         ArrayList<E> result = copy();
-        result.add(other._array, other._size);
+        result += other;
         return result;
     }
-    bool contains(E element) { return indexOf(element) >= 0; }
-    int indexOfInRange(E element, int start, int stop) {
+    bool contains(const E &element) { return indexOf(element) >= 0; }
+    int indexOfInRange(const E &element, int start, int stop) {
         for (int i = start; i < stop; i++)
             if (_array[i] == element)
                 return i;
         return -1;
     }
-    int indexOf(E element) { return indexOfInRange(element, 0, _size); }
-    int lastIndexOfInRange(E element, int start, int stop) {
+    int indexOf(const E &element) { return indexOfInRange(element, 0, _size); }
+    int lastIndexOfInRange(const E &element, int start, int stop) {
         for (int i = stop - 1; i >= start; i--)
             if (_array[i] == element)
                 return i;
         return -1;
     }
-    int lastIndexOf(E element) { return lastIndexOfInRange(element, 0, _size); }
-    ArrayList<E> copy() { return ArrayList<E>(this); }
+    int lastIndexOf(const E &element) { return lastIndexOfInRange(element, 0, _size); }
+    ArrayList<E> copy() { return ArrayList<E>(reinterpret_cast<size_t>(this)); }
+    ArrayList<E> operator+(const E &element) {
+        ArrayList<E> result = copy();
+        result += element;
+        return result;
+    }
     ArrayList<E> operator+(const ArrayList<E> &other) { return add(other); }
+    ArrayList<E> &operator+=(const E &element) {
+        add(element);
+        return *this;
+    }
+    ArrayList<E> &operator+=(const ArrayList<E> &other) {
+        add(other._array, other._size);
+        return *this;
+    }
     ArrayList<E> &operator=(const ArrayList<E> &other) {
         if (this != &other) {
             ensureCapacityInternal(other._capacity);
-            memcpy(_array, other._array, _size * sizeof(E));
+            if (other._size > 0)
+                memcpy(_array, other._array, _size * sizeof(E));
         }
         return *this;
     }
+    E *begin() { return _array; }
+    E *end() { return _array + _size; }
+    const E *begin() const { return _array; }
+    const E *end() const { return _array + _size; }
 };
 
 
diff --git a/src/Controller.h b/src/Controller.h
index b76b214..905bb78 100644
--- a/src/Controller.h
+++ b/src/Controller.h
@@ -9,7 +9,7 @@ class Controller : public Device<T> {
 protected:
     ArrayList<String> _device_tags;
     ArrayList<Device<E>> _devices;
-    void _attachDevice(String &tag, Device<E> device) {
+    void _attachDevice(const String &tag, Device<E> device) {
         _device_tags.add(tag);
         _devices.add(device);
         device.tag(tag);
@@ -18,15 +18,13 @@ class Controller : public Device<T> {
 public:
     Controller() : Device<T>() {}
     int level() { return this->_parentTags.size(); }
-    void device(const String &tag, Device<E> device) { _attachDevice(tag, device); }
+    const ArrayList<Device<E>> &devices() { return _devices; }
+    void device(const String &tag, const Device<E> &device) { _attachDevice(tag, device); }
     Device<E> device(const String &tag) { return _devices.get(_device_tags.indexOf(tag)); }
-    virtual void initialize(const ArrayList<String> &parentTags) {
+    void initialize(const ArrayList<String> &parentTags) override {
         Device<E>::initialize(parentTags);
-        for (Device<E> d: _devices) {
-            ArrayList<String> deviceParentTags = this->_parentTags.copy();
-            deviceParentTags.add(this->_tag);
-            d.initialize(deviceParentTags);
-        }
+        for (Device<E> d: _devices)
+            d.initialize(this->_parentTags + this->_tag);
     }
 };
 
diff --git a/src/Device.h b/src/Device.h
index f195dc5..ec47040 100644
--- a/src/Device.h
+++ b/src/Device.h
@@ -8,19 +8,21 @@ template<typename T>
 class Device {
 protected:
     String _tag = "";
-    ArrayList<String> _parentTags = ArrayList<String>();
+    ArrayList<String> _parentTags = ArrayList<String>(0);
     ArrayList<int> _pins;
 
 public:
     explicit Device(const ArrayList<int> &pins) : _pins(pins) {}
+    Device() : Device(ArrayList<int>(0)) {}
     ~Device() = default;
     void tag(const String &tag) { _tag = tag; }
     String tag() { return _tag; }
-    void parentTags(const ArrayList<String> &parentTags) { _parentTags = parentTags; }
     const ArrayList<String> &parentTags() { return _parentTags; }
     virtual void initialize(const ArrayList<String> &parentTags) { _parentTags = parentTags; }
-    virtual T read() = 0;
+    void initializeAsRoot() { initialize(ArrayList<String>(0)); }
+    virtual T read() { return T(); }
     virtual void write(T payload) {}
+    virtual void update(T data) {}
     virtual void close() {}
 };
 
diff --git a/src/LEADS.h b/src/LEADS.h
index ab7a810..53b2951 100644
--- a/src/LEADS.h
+++ b/src/LEADS.h
@@ -1,5 +1,6 @@
 #include "Controller.h"
 #include "Device.h"
+#include "Peer.h"
 #include "PredefinedTags.h"
 #include "Utils.h"
 #include "VoltageSensor.h"
diff --git a/src/Peer.cpp b/src/Peer.cpp
new file mode 100644
index 0000000..dd3743a
--- /dev/null
+++ b/src/Peer.cpp
@@ -0,0 +1,29 @@
+#include "Peer.h"
+
+
+Peer::Peer(unsigned int baudRate, String separator, String remainder) :
+    Controller<String, String>(), _baudRate(baudRate), _separator(separator), _remainder(remainder) {}
+void Peer::initialize(const ArrayList<String> &parentTags) {
+    Controller<String, String>::initialize(parentTags);
+    Serial.begin(_baudRate);
+}
+String Peer::read() {
+    char c = Serial.read();
+    if (c > 0) {
+        _remainder += c;
+        if (!_remainder.endsWith(_separator))
+            return "";
+        String result = _remainder.substring(0, _remainder.length() - _separator.length());
+        _remainder = "";
+        return result;
+    }
+    return "";
+}
+void Peer::write(String payload) { Serial.print(payload + _separator); }
+void Peer::refresh() {
+    String msg = read();
+    if (msg == "")
+        return;
+    for (Device<String> d: _devices)
+        d.update(msg);
+}
diff --git a/src/Peer.h b/src/Peer.h
new file mode 100644
index 0000000..8a0554b
--- /dev/null
+++ b/src/Peer.h
@@ -0,0 +1,22 @@
+#ifndef PEER_H
+#define PEER_H
+
+
+#include "Controller.h"
+
+// although we try to keep a consistent format, the C++ version does not support multithreading
+class Peer : public Controller<String, String> {
+protected:
+    unsigned int _baudRate;
+    String _separator, _remainder;
+
+public:
+    explicit Peer(unsigned int baudRate = 9600, String separator = ";", String remainder = "");
+    void initialize(const ArrayList<String> &parentTags) override;
+    String read() override;
+    void write(String payload) override;
+    void refresh();
+};
+
+
+#endif // PEER_H
diff --git a/src/Utils.cpp b/src/Utils.cpp
index b814633..f558f4e 100644
--- a/src/Utils.cpp
+++ b/src/Utils.cpp
@@ -2,18 +2,6 @@
 
 bool pulseTriggered(int pin) { return digitalRead(pin) == LOW; }
 
-bool equivalent(float a, float b, float epsilon) { return abs(a - b) <= epsilon * max(abs(a), abs(b)); }
+void returnFloat(Peer peer, const String &tag, float n) { peer.write(tag + ":" + n); }
 
-bool equivalent(long a, long b, float epsilon) { return labs(a - b) <= epsilon * max(labs(a), labs(b)); }
-
-void returnFloat(const String &tag, float n) {
-    Serial.print(tag + ":");
-    Serial.print(n);
-    Serial.print(";");
-}
-
-void returnDouble(const String &tag, double n) {
-    Serial.print(tag + ":");
-    Serial.print(n);
-    Serial.print(";");
-}
+void returnDouble(Peer peer, const String &tag, double n) { peer.write(tag + ":" + n); }
diff --git a/src/Utils.h b/src/Utils.h
index 6f718d4..826439f 100644
--- a/src/Utils.h
+++ b/src/Utils.h
@@ -3,16 +3,13 @@
 
 
 #include "Arduino.h"
+#include "Peer.h"
 
 bool pulseTriggered(int pin);
 
-bool equivalent(long a, long b, float epsilon);
+void returnFloat(Peer peer, const String &tag, float n);
 
-bool equivalent(float a, float b, float epsilon);
-
-void returnFloat(const String &tag, float n);
-
-void returnDouble(const String &tag, double n);
+void returnDouble(Peer peer, const String &tag, double n);
 
 
 #endif // UTILS_H