Add reconnect if the connection dies

this time, by recalling mqtt.connect

apparently it didn't like recreating the objects very much

autoplant_pio/src/autoplant.cpp

@@ -57,10 +57,10 @@
 // Ref https://stackoverflow.com/a/523737/1460422
 #define CHECK_BIT(var,pos) ((var) & (1<<(pos)))
 
-#ifndef MQTT_NO_TLS
+#ifdef MQTT_NO_TLS
-WiFiClientSecure transport;
-#else
 WiFiClient transport;
+#else
+WiFiClientSecure transport;
 #endif
 PubSubClient mqtt;
 
@@ -113,6 +113,40 @@ float read_analog(int channel) {
 	return parsedValue;
 }
 
+void connect_mqtt() {
+	if(!mqtt.connect(
+		("autoplant_" + String(random(0, 999999))).c_str(),
+		MQTT_USERNAME, MQTT_PASSWORD)
+	) {
+		/* Ref https://pubsubclient.knolleary.net/api#state
+		-4 : MQTT_CONNECTION_TIMEOUT - the server didn't respond within the keepalive time
+		-3 : MQTT_CONNECTION_LOST - the network connection was broken
+		-2 : MQTT_CONNECT_FAILED - the network connection failed
+		-1 : MQTT_DISCONNECTED - the client is disconnected cleanly
+		0 : MQTT_CONNECTED - the client is connected
+		1 : MQTT_CONNECT_BAD_PROTOCOL - the server doesn't support the requested version of MQTT
+		2 : MQTT_CONNECT_BAD_CLIENT_ID - the server rejected the client identifier
+		3 : MQTT_CONNECT_UNAVAILABLE - the server was unable to accept the connection
+		4 : MQTT_CONNECT_BAD_CREDENTIALS - the username/password were rejected
+		5 : MQTT_CONNECT_UNAUTHORIZED - the client was not authorized to connect
+		*/
+		int error_code = mqtt.state();
+		Serial.println("failed, error code "+String(error_code));
+		while(true) delay(10000);
+	}
+	Serial.println("ok");
+}
+
+void check_mqtt() {
+	if(mqtt.connected() == 0) {
+		Serial.print("MQTT reconnect: ");
+		connect_mqtt();
+	}
+	else {
+		Serial.println("MQTT: connection ok");
+	}
+}
+
 bool send_mqtt(String id, String sensor, float value) {
 	// StaticJsonDocument<96> data;
 	// 
@@ -125,6 +159,7 @@ bool send_mqtt(String id, String sensor, float value) {
 	// char* payload = new char[length]();
 	// serializeJson(data, payload, length);
 	
+	check_mqtt();
 	bool result = mqtt.publish("sensors/data", payload.c_str());
 	// delete[] payload;
 	
@@ -177,32 +212,13 @@ void setup() {
 	// mqtt.setBufferSize(1000);
 	mqtt.setClient(transport); Serial.print(".");
 	mqtt.setServer(MQTT_SERVER, MQTT_PORT); Serial.print(".");
+	mqtt.setKeepAlive(INTERVAL / 2);
 	// Serial.print(MQTT_SERVER);
 	// Serial.print(":");
 	// Serial.print(MQTT_PORT);
 	// Serial.print(".");
 	
-	if(!mqtt.connect(
+	connect_mqtt();
-		("autoplant_" + String(random(0, 999999))).c_str(),
-		MQTT_USERNAME, MQTT_PASSWORD)
-	) {
-		/* Ref https://pubsubclient.knolleary.net/api#state
-		-4 : MQTT_CONNECTION_TIMEOUT - the server didn't respond within the keepalive time
-		-3 : MQTT_CONNECTION_LOST - the network connection was broken
-		-2 : MQTT_CONNECT_FAILED - the network connection failed
-		-1 : MQTT_DISCONNECTED - the client is disconnected cleanly
-		0 : MQTT_CONNECTED - the client is connected
-		1 : MQTT_CONNECT_BAD_PROTOCOL - the server doesn't support the requested version of MQTT
-		2 : MQTT_CONNECT_BAD_CLIENT_ID - the server rejected the client identifier
-		3 : MQTT_CONNECT_UNAVAILABLE - the server was unable to accept the connection
-		4 : MQTT_CONNECT_BAD_CREDENTIALS - the username/password were rejected
-		5 : MQTT_CONNECT_UNAUTHORIZED - the client was not authorized to connect
-		*/
-		int error_code = mqtt.state();
-		Serial.println("failed, error code "+String(error_code));
-		while(true) delay(10000);
-	}
-	Serial.println("ok");
 	
 	Serial.print("BME280: ");