From d513fce941d52e6f2fb5e62372282cd22bbea7a7 Mon Sep 17 00:00:00 2001
From: Chris Giacofei <c.giacofei@gmail.com>
Date: Tue, 11 Jan 2022 12:10:24 -0500
Subject: [PATCH] Now it compiles.

---
 boil_kettle/mqtt.ino | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/boil_kettle/mqtt.ino b/boil_kettle/mqtt.ino
index ed6eeae..c24a5ca 100644
--- a/boil_kettle/mqtt.ino
+++ b/boil_kettle/mqtt.ino
@@ -1,3 +1,10 @@
+char * Concatenate(char *first, char *second) {
+  static char buf[30];
+  strcpy(buf,first);
+  strcat(buf,second);
+  return buf;
+}
+
 void ConnectMQTT() {
   Serial.println("connecting MQTT...");
   while (!mqtt_client.connect("brewhouse", MQTT_USER, MQTT_PASSWORD)) {
@@ -7,8 +14,7 @@ void ConnectMQTT() {
 
   Serial.println("\nconnected!");
 
-  String topic = TOPIC_PREFIX + BKTOPIC;
-  mqtt_client.subscribe(topic);
+  mqtt_client.subscribe(Concatenate(TOPIC_PREFIX, BKTOPIC));
 }
 
 void MessageReceived(String &topic, String &payload) {
@@ -27,9 +33,7 @@ void MessageReceived(String &topic, String &payload) {
     return;
   }
 
-  String subscribed = TOPIC_PREFIX + BKTOPIC;
-
-  if (topic == subscribed) {
+  if (topic == Concatenate(TOPIC_PREFIX, BKTOPIC)) {
     // Update PWM setpoint.
     String name = doc["entity"];
     String setting = doc["setpoint"];
@@ -41,7 +45,7 @@ void MessageReceived(String &topic, String &payload) {
   }
 }
 
-void SetupMQTT(String broker) {
+void SetupMQTT(char *broker) {
   // Note: Local domain names (e.g. "Computer.local" on OSX) are not supported
   // by Arduino. You need to set the IP address directly.
   Serial.println("Setup MQTT client.");
@@ -64,9 +68,6 @@ static void SendSensorData() {
   String jstr;
   serializeJson(doc, jstr);
 
-  String topic = TOPIC_PREFIX;
-  topic += "sensor/boil_kettle";
-
-  mqtt_client.publish(topic, jstr);
+  mqtt_client.publish(Concatenate(TOPIC_PREFIX, "sensor/boil_kettle"), jstr);
 
 }