make MQTT settings configurable, needs serious cleanup now

things.ino

@@ -1,5 +1,6 @@
 // based on example code from the used libraries
 
+#include <FS.h>                 // this needs to be first, or it all crashes and burns...
 extern "C" {
   #include <user_interface.h>
 }
@@ -10,6 +11,7 @@ extern "C" {
 #include <Ticker.h>
 #include <PubSubClient.h>       // https://github.com/knolleary/pubsubclient
 #include <DHT.h>                // https://github.com/adafruit/DHT-sensor-library
+#include <ArduinoJson.h>        // https://github.com/bblanchon/ArduinoJson
 
 // configure DHT sensor
 #define DHTPIN D4       // what pin the DHT is connected to
@@ -17,7 +19,19 @@ extern "C" {
 //#define DHTTYPE DHT21 // DHT21 (AM2301)
 #define DHTTYPE DHT22   // DHT22 (AM2302)
 
-const char* mqtt_server = "192.168.0.66";
+//define your default values here, if there are different values in config.json, they are overwritten.
+char mqtt_server[40];
+char mqtt_port[6] = "1883";
+char mqtt_topic[34] = "OutTopic";
+
+//flag for saving data
+bool shouldSaveConfig = false;
+
+//callback notifying us of the need to save config
+void saveConfigCallback () {
+  Serial.println("Should save config");
+  shouldSaveConfig = true;
+}
 
 // initialize modules
 ESP8266WebServer server(80);    // webserver
@@ -82,14 +96,21 @@ void read_sensor() {
     dtostrf(temperature, 1, 2, str_temperature);
     dtostrf(heatindex, 1, 2, str_heatindex);
 
+        char pub_topic[34];
     if (!isEqual(humidity, previousHumidity)) {
-      client.publish("nodemcu/humidity", str_humidity);
+        strcpy(pub_topic,mqtt_topic);
+        strcat(pub_topic,"/humidity");
+      client.publish(pub_topic, str_humidity);
     }
     if (!isEqual(temperature, previousTemperature)) {
-      client.publish("nodemcu/temperature", str_temperature);
+        strcpy(pub_topic,mqtt_topic);
+        strcat(pub_topic,"/temperature");
+      client.publish(pub_topic, str_temperature);
     }
     if (!isEqual(heatindex, previousHeatindex)) {
-      client.publish("nodemcu/heatindex", str_heatindex);
+        strcpy(pub_topic,mqtt_topic);
+        strcat(pub_topic,"/heatindex");
+      client.publish(pub_topic, str_heatindex);
     }
 
     Serial.print("Humidity: ");
@@ -130,10 +151,13 @@ void reconnect() {
   while (!client.connected()) {
     Serial.print("Attempting MQTT connection...");
     // Attempt to connect
-    if (client.connect(wifi_station_get_hostname(), "nodemcu/online", MQTTQOS1, true, "0")) {
+        char pub_topic[34];
+        strcpy(pub_topic,mqtt_topic);
+        strcat(pub_topic,"/online");
+    if (client.connect(wifi_station_get_hostname(), pub_topic, MQTTQOS1, true, "0")) {
       Serial.println("connected");
       // Once connected, publish an announcement...
-      client.publish("nodemcu/online", "1");
+      client.publish(pub_topic, "1");
       // ... and resubscribe:
       client.subscribe("inTopic");
     } else {
@@ -146,6 +170,18 @@ void reconnect() {
   }
 }
 
+    int stringToNumber(String thisString) {
+      int i, value, length;
+      length = thisString.length();
+      char blah[(length + 1)];
+      for (i = 0; i < length; i++) {
+        blah[i] = thisString.charAt(i);
+      }
+      blah[i] = 0;
+      value = atoi(blah);
+      return value;
+    }
+    
 void setup() {
   // put your setup code here, to run once:
   Serial.begin(9600);
@@ -155,6 +191,53 @@ void setup() {
   // start ticker with 0.5 because we start in AP mode and try to connect
   ticker.attach(0.6, toggle_led);
 
+
+      //clean FS, for testing
+      //SPIFFS.format();
+
+      //read configuration from FS json
+      Serial.println("mounting FS...");
+
+      if (SPIFFS.begin()) {
+        Serial.println("mounted file system");
+        if (SPIFFS.exists("/config.json")) {
+          //file exists, reading and loading
+          Serial.println("reading config file");
+          File configFile = SPIFFS.open("/config.json", "r");
+          if (configFile) {
+            Serial.println("opened config file");
+            size_t size = configFile.size();
+            // Allocate a buffer to store contents of the file.
+            std::unique_ptr<char[]> buf(new char[size]);
+
+            configFile.readBytes(buf.get(), size);
+            DynamicJsonBuffer jsonBuffer;
+            JsonObject& json = jsonBuffer.parseObject(buf.get());
+            json.printTo(Serial);
+            if (json.success()) {
+              Serial.println("\nparsed json");
+
+              strcpy(mqtt_server, json["mqtt_server"]);
+              strcpy(mqtt_port, json["mqtt_port"]);
+              strcpy(mqtt_topic, json["mqtt_topic"]);
+
+            } else {
+              Serial.println("failed to load json config");
+            }
+          }
+        }
+      } else {
+        Serial.println("failed to mount FS");
+      }
+      //end read
+
+      // The extra parameters to be configured (can be either global or just in the setup)
+      // After connecting, parameter.getValue() will get you the configured value
+      // id/name placeholder/prompt default length
+      WiFiManagerParameter custom_mqtt_server("server", "mqtt server", mqtt_server, 40);
+      WiFiManagerParameter custom_mqtt_port("port", "mqtt port", mqtt_port, 5);
+      WiFiManagerParameter custom_mqtt_topic("topic", "mqtt topic", mqtt_topic, 32);
+
   //WiFiManager
   //Local intialization. Once its business is done, there is no need to keep it around
   WiFiManager wifiManager;
@@ -164,6 +247,14 @@ void setup() {
   //set callback that gets called when connecting to previous WiFi fails, and enters Access Point mode
   wifiManager.setAPCallback(configModeCallback);
 
+      //set config save notify callback
+      wifiManager.setSaveConfigCallback(saveConfigCallback);
+
+      //add all your parameters here
+      wifiManager.addParameter(&custom_mqtt_server);
+      wifiManager.addParameter(&custom_mqtt_port);
+      wifiManager.addParameter(&custom_mqtt_topic);
+
   //fetches ssid and pass and tries to connect
   //if it does not connect it starts an access point with the specified name
   //here  "AutoConnectAP"
@@ -181,16 +272,48 @@ void setup() {
   //keep LED on
   digitalWrite(BUILTIN_LED, LOW);
 
-  client.setServer(mqtt_server, 1883);
+      //read updated parameters
+      strcpy(mqtt_server, custom_mqtt_server.getValue());
+      strcpy(mqtt_port, custom_mqtt_port.getValue());
+      strcpy(mqtt_topic, custom_mqtt_topic.getValue());
+
+      //save the custom parameters to FS
+      if (shouldSaveConfig) {
+        Serial.println("saving config");
+        DynamicJsonBuffer jsonBuffer;
+        JsonObject& json = jsonBuffer.createObject();
+        json["mqtt_server"] = mqtt_server;
+        json["mqtt_port"] = mqtt_port;
+        json["mqtt_topic"] = mqtt_topic;
+
+        File configFile = SPIFFS.open("/config.json", "w");
+        if (!configFile) {
+          Serial.println("failed to open config file for writing");
+        }
+
+        json.printTo(Serial);
+        json.printTo(configFile);
+        configFile.close();
+        //end save
+      }
+
+  client.setServer(mqtt_server, stringToNumber(mqtt_port));
   client.setCallback(callback);
 
   dht.begin();
 
   // Initial read
   read_sensor();
-  client.publish("nodemcu/humidity", str_humidity);
-  client.publish("nodemcu/temperature", str_temperature);
-  client.publish("nodemcu/heatindex", str_heatindex);
+        char pub_topic[34];
+        strcpy(pub_topic,mqtt_topic);
+        strcat(pub_topic,"/humidity");
+  client.publish(pub_topic, str_humidity);
+        strcpy(pub_topic,mqtt_topic);
+        strcat(pub_topic,"/temperature");
+  client.publish(pub_topic, str_temperature);
+        strcpy(pub_topic,mqtt_topic);
+        strcat(pub_topic,"/heatindex");
+  client.publish(pub_topic, str_heatindex);
 
   // Handle http requests
   server.on("/", [](){