From 08990a7a93d964dc6c311a879670657aedfce01a Mon Sep 17 00:00:00 2001
From: damage <damage@devloop.de>
Date: Sat, 17 May 2025 15:17:13 +0200
Subject: [PATCH] keepalive is called by mqtt poll

manual keepliave not needed anymore
---
 master/master.ino | 30 ++++++++++--------------------
 1 file changed, 10 insertions(+), 20 deletions(-)

diff --git a/master/master.ino b/master/master.ino
index a8d969c..29ad94d 100644
--- a/master/master.ino
+++ b/master/master.ino
@@ -19,7 +19,7 @@
 #define MQTT_SIM_LOG_TOPIC "/xplane/meta/log"
 #define MQTT_SIM_VALUE_TOPIC "/xplane/rref/#"
 
-#define MQTT_KEEPALIVE_INTERVAL_LOOPS 60000
+#define MQTT_KEEPALIVE_INTERVAL_MS 15000
 
 struct device {
   byte address;       // I2C address of device
@@ -35,19 +35,12 @@ struct device {
 struct device devices[] = {
   { 0x08, "Heading Speed", {'H', 'D', 'G'}, HEADING_SIM_UP, HEADING_SIM_DOWN, {'S', 'P', 'D'}, AIRSPEED_SIM_UP, AIRSPEED_SIM_DOWN }
 };
-
-int numDevices = -1;
+int numDevices = -1; // gets calculated in setup()
 
 byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
-
-const char broker[] = "openhab.sugarland.lan";
-int        port     = 1883;
-const char topic[]  = MQTT_SIM_VALUE_TOPIC;
-
 EthernetClient client;
-char localIP[16];
+
 MqttClient mqttClient(client);
-int mqttLastKeepAlive = 0;
 
 void onMqttMessage(int messageSize) {
 //  // we received a message, print out the topic and contents
@@ -99,6 +92,7 @@ void setup() {
     while (1);
   }
   // print your local IP address:
+  char localIP[16];
   sprintf(localIP, "%d.%d.%d.%d", Ethernet.localIP()[0], Ethernet.localIP()[1], Ethernet.localIP()[2], Ethernet.localIP()[3]);
   Serial.println(localIP);
 
@@ -106,7 +100,7 @@ void setup() {
   mqttClient.setUsernamePassword(MQTT_USER, MQTT_PASS);
 
   // MQTT connection
-  if (!mqttClient.connect(broker, port)) {
+  if (!mqttClient.connect(MQTT_SERVER, MQTT_PORT)) {
     Serial.print("MQTT connection failed! Error code = ");
     Serial.println(mqttClient.connectError());
 
@@ -118,8 +112,8 @@ void setup() {
 
   // subscribe to MQTT topic
   mqttClient.onMessage(onMqttMessage);
-  mqttClient.subscribe(topic);
-  mqttClient.setKeepAliveInterval(10 * 1000L);
+  mqttClient.subscribe(MQTT_SIM_VALUE_TOPIC);
+  mqttClient.setKeepAliveInterval(MQTT_KEEPALIVE_INTERVAL_MS);
 
   // start I2C
   Wire.begin();
@@ -174,11 +168,7 @@ void loop() {
     }
   }
 
-  // transmit MQTT keepalive message every MQTT_KEEPALIVE_INTERVAL_LOOPS times
-  // running the loop
-  mqttLastKeepAlive++;
-  if (mqttLastKeepAlive >= MQTT_KEEPALIVE_INTERVAL_LOOPS) {
-    sendMqttMessage(MQTT_SIM_DEVICE_TOPIC, 1, localIP);
-    mqttLastKeepAlive = 0;
-  }
+  // call poll() regularly to allow the library to receive MQTT messages and
+  // send MQTT keep alives which avoids being disconnected by the broker
+  mqttClient.poll();
 }