diff --git a/readref.c b/readref.c
index 1877f15..c775a5c 100644
--- a/readref.c
+++ b/readref.c
@@ -24,6 +24,15 @@ const int MQTT_RREF_REQUEST_MIN_LENGTH = MQTT_RREF_REQUEST_LENGTH_ID + MQTT_RREF
 int xPlaneSocket;
 struct mosquitto *mqtt;
 
+struct valueCacheElement
+{
+    float value;
+    bool force;
+};
+
+struct valueCacheElement *valueCache = NULL;
+int valueCacheCount = 0;
+
 #define XPLANE_RREF_MAX_LENGTH 400
 struct dref_struct_in
 {
@@ -49,7 +58,8 @@ int *strtoint(char *in, size_t start, size_t n)
         return NULL;
     }
 
-    for (int i = 0; i < n; i++) {
+    for (int i = 0; i < n; i++)
+    {
         int position = offset - i;
         if (in[position] >= '0' && in[position] <= '9')
         {
@@ -66,22 +76,27 @@ int *strtoint(char *in, size_t start, size_t n)
 
 void requestRrefFromXPlane(const struct mosquitto_message *message)
 {
-    int *id, *frequency;
+    int *index, *frequency;
 
     if (message->payloadlen >= MQTT_RREF_REQUEST_MIN_LENGTH)
     {
-        id = strtoint(message->payload, MQTT_RREF_REQUEST_START_ID, MQTT_RREF_REQUEST_LENGTH_ID);
+        index = strtoint(message->payload, MQTT_RREF_REQUEST_START_ID, MQTT_RREF_REQUEST_LENGTH_ID);
         frequency = strtoint(message->payload, MQTT_RREF_REQUEST_START_FREQ, MQTT_RREF_REQUEST_LENGTH_FREQ);
 
-        if (id == NULL || frequency == NULL) {
+        if (index == NULL || frequency == NULL)
+        {
             return;
         }
 
+        if (*index < valueCacheCount)
+        {
+            valueCache[*index].force = true;
+        }
+
         // prepare struct to send, make sure padding is with NULL bytes
         struct dref_struct_in drefToRead = {
             .dref_freq = *frequency,
-            .dref_sender_index = *id
-        };
+            .dref_sender_index = *index};
         memset(drefToRead.dref_string, 0, sizeof(drefToRead.dref_string));
         strncpy(drefToRead.dref_string, &((char *)message->payload)[MQTT_RREF_REQUEST_START_RREF], message->payloadlen - MQTT_RREF_REQUEST_START_RREF);
 
@@ -93,7 +108,8 @@ void sendCommandToXPlane(const struct mosquitto_message *message)
 {
     char *command;
 
-    if (message->payloadlen > 0) {
+    if (message->payloadlen > 0)
+    {
         sendToXPlane(xPlaneSocket, DEST_SERVER, DEST_PORT, "CMND", (char *)message->payload, message->payloadlen);
     }
 }
@@ -167,12 +183,37 @@ int main()
                         struct dref_struct_out drefRead;
                         memcpy(&drefRead, &payload[i], sizeof(struct dref_struct_out));
 
-                        printf("%d: %f\n", drefRead.dref_sender_index, drefRead.dref_flt_value);
+                        // add new element to array
+                        if (valueCache == NULL)
+                        {
+                            valueCacheCount = drefRead.dref_sender_index + 10;
+                            valueCache = calloc(valueCacheCount, sizeof(struct valueCacheElement));
+                        }
+                        else if (drefRead.dref_sender_index >= valueCacheCount)
+                        {
+                            valueCacheCount = drefRead.dref_sender_index + 10;
+                            valueCache = reallocarray(valueCache, valueCacheCount, sizeof(struct valueCacheElement));
+                        }
+                        else
+                        {
+                            // size of array is sufficient
+                        }
 
-                        sprintf(mqttTopic, "/xplane/rref/%d", drefRead.dref_sender_index);
-                        sprintf(mqttPayload, "%f", drefRead.dref_flt_value);
+                        if (valueCache[drefRead.dref_sender_index].force || valueCache[drefRead.dref_sender_index].value != drefRead.dref_flt_value)
+                        {
+                            valueCache[drefRead.dref_sender_index].value = drefRead.dref_flt_value;
+                            printf("%d: %f\n", drefRead.dref_sender_index, drefRead.dref_flt_value);
 
-                        sendMqtt(mqtt, mqttTopic, mqttPayload, strlen(mqttPayload));
+                            sprintf(mqttTopic, "/xplane/rref/%d", drefRead.dref_sender_index);
+                            sprintf(mqttPayload, "%f", drefRead.dref_flt_value);
+
+                            sendMqtt(mqtt, mqttTopic, mqttPayload, strlen(mqttPayload));
+                            valueCache[drefRead.dref_sender_index].force = false;
+                        }
+                        else
+                        {
+                            // neither changed nor forced
+                        }
                     }
                 }
                 else
@@ -190,7 +231,7 @@ int main()
             exit(EXIT_FAILURE);
         }
 
-        mosquitto_loop(mqtt, 100, 1);
+        mosquitto_loop(mqtt, 0, 1);
     }
 
     // bye bye (and no, I don't care about error anymore; I'll exit anyway?!)