diff --git a/NodeManager.cpp b/NodeManager.cpp
index 0624c7a0209098a5c627d91726789f31edec5ee3..7a6b3f6d50847eb77874c9da431c5f1cd03960d2 100644
--- a/NodeManager.cpp
+++ b/NodeManager.cpp
@@ -2193,7 +2193,7 @@ void NodeManager::before() {
     if (! _battery_internal_vcc && _battery_pin > -1) analogReference(INTERNAL);
   #endif
   // setup individual sensors
-  for (int i = 0; i < 255; i++) {
+  for (int i = 0; i < MAX_SENSORS; i++) {
     if (_sensors[i] == 0) continue;
     // call each sensor's setup()
     _sensors[i]->before();
@@ -2217,7 +2217,7 @@ void NodeManager::presentation() {
     _process("BATTERY");
   #endif
   // present each sensor
-  for (int i = 0; i < 255; i++) {
+  for (int i = 0; i < MAX_SENSORS; i++) {
     if (_sensors[i] == 0) continue;
     // call each sensor's presentation()
     if (_sleep_between_send > 0) sleep(_sleep_between_send);
@@ -2242,7 +2242,7 @@ void NodeManager::setup() {
     _send(_msg.set("STARTED"));
   #endif
   // run setup for all the registered sensors
-  for (int i = 0; i < 255; i++) {
+  for (int i = 0; i < MAX_SENSORS; i++) {
     if (_sensors[i] == 0) continue;
     // call each sensor's setup()
     _sensors[i]->setup();
@@ -2261,7 +2261,7 @@ void NodeManager::loop() {
       if (_auto_power_pins) powerOn();
     #endif
     // run loop for all the registered sensors
-    for (int i = 0; i < 255; i++) {
+    for (int i = 0; i < MAX_SENSORS; i++) {
       // skip not configured sensors
       if (_sensors[i] == 0) continue;
       // if waking up from an interrupt skip all the sensor without that interrupt configured
@@ -2609,7 +2609,7 @@ void NodeManager::_present(int child_id, int type) {
 
 // return the next available child_id
 int NodeManager::_getAvailableChildId() {
-  for (int i = 1; i < 255; i++) {
+  for (int i = 1; i < MAX_SENSORS; i++) {
     if (i == CONFIGURATION_CHILD_ID) continue;
     if (i == BATTERY_CHILD_ID) continue;
     // empty place, return it
diff --git a/NodeManager.h b/NodeManager.h
index 6bf3edd598dea61311d8d1aa763df951934fe009..c27da05bced5a84f3b9e3478013d9cae98a576fd 100644
--- a/NodeManager.h
+++ b/NodeManager.h
@@ -51,6 +51,10 @@
 /***********************************
    Default configuration settings
 */
+// if enabled, enable debug messages on serial port
+#ifndef DEBUG
+  #define DEBUG 1
+#endif
 
 // if enabled, enable the capability to power on sensors with the arduino's pins to save battery while sleeping
 #ifndef POWER_MANAGER
@@ -69,29 +73,15 @@
   #define PERSIST 0
 #endif
 
-// if enabled, enable debug messages on serial port
-#ifndef DEBUG
-  #define DEBUG 1
-#endif
-
 // if enabled, send a SLEEPING and AWAKE service messages just before entering and just after leaving a sleep cycle
 #ifndef SERVICE_MESSAGES
-  #define SERVICE_MESSAGES 1
+  #define SERVICE_MESSAGES 0
 #endif
 // if enabled, a battery sensor will be created at BATTERY_CHILD_ID and will report vcc voltage together with the battery level percentage
 #ifndef BATTERY_SENSOR
   #define BATTERY_SENSOR 1
 #endif
 
-// the child id used to allow remote configuration
-#ifndef CONFIGURATION_CHILD_ID
-  #define CONFIGURATION_CHILD_ID 200
-#endif
-// the child id used to report the battery voltage to the controller
-#ifndef BATTERY_CHILD_ID
-  #define BATTERY_CHILD_ID 201
-#endif
-
 // Enable this module to use one of the following sensors: SENSOR_ANALOG_INPUT, SENSOR_LDR, SENSOR_THERMISTOR, SENSOR_MQ, SENSOR_ACS712
 #ifndef MODULE_ANALOG_INPUT
   #define MODULE_ANALOG_INPUT 0
@@ -149,6 +139,19 @@
   #define MODULE_MCP9808 0
 #endif
 
+// the child id used to allow remote configuration
+#ifndef CONFIGURATION_CHILD_ID
+  #define CONFIGURATION_CHILD_ID 200
+#endif
+// the child id used to report the battery voltage to the controller
+#ifndef BATTERY_CHILD_ID
+  #define BATTERY_CHILD_ID 201
+#endif
+// define the maximum number of sensors that can be managed
+#ifndef MAX_SENSORS
+  #define MAX_SENSORS 10
+#endif
+
 /***********************************
    Sensors types
 */
@@ -1063,7 +1066,7 @@ class NodeManager {
     int _interrupt_2_pull = -1;
     int _last_interrupt_pin = -1;
     long _timestamp = -1;
-    Sensor* _sensors[255] = {0};
+    Sensor* _sensors[MAX_SENSORS] = {0};
     bool _ack = false;
     void _process(const char * message);
     void _sleep();