Adding MQTT_TOPIC_PREFIX in config

ampel-firmware/config.public.h

@@ -41,8 +41,8 @@
 // AMPEL_CONFIG_VERSION should be defined, and have exactly 3 characters.
 // If you modify this string, every parameter saved on the Ampel will be replaced by the ones in config.h.
 // AMPEL_CONFIG_VERSION should also be updated if the configuration structure is modified.
-// The structure of the Ampel configuration has been modified 10 times, so it's called "a10" for now.
-#  define AMPEL_CONFIG_VERSION "a10"
+// The structure of the Ampel configuration has been modified 11 times, so it's called "a11" for now.
+#  define AMPEL_CONFIG_VERSION "a11"
 
 /**
  * SERVICES
@@ -150,6 +150,7 @@
 #  define MQTT_ENCRYPTED true // Set to false for unencrypted MQTT (e.g. with port 1883).
 #  define MQTT_USER ""
 #  define MQTT_PASSWORD ""
+#  define MQTT_TOPIC_PREFIX "CO2sensors/" // ESPxxxxxx will be added to the prefix, so complete topic will be "CO2sensors/ESPxxxxxx"
 
 /**
  * LoRaWAN

ampel-firmware/mqtt.cpp

@@ -33,13 +33,13 @@ namespace mqtt {
   unsigned long last_failed_at = 0;
   bool connected = false;
 
-  char publish_topic[21]; // e.g. "CO2sensors/ESPxxxxxx\0"
+  char publish_topic[42]; // "MQTT_TOPIC_PREFIX/ESPxxxxxx\0", e.g. "CO2sensors/ESPxxxxxx\0"
   const char *json_sensor_format;
   char last_successful_publish[23] = "";
 
   void initialize(const char *sensorId) {
     json_sensor_format = PSTR("{\"time\":\"%s\", \"co2\":%d, \"temp\":%.1f, \"rh\":%.1f}");
-    snprintf(publish_topic, sizeof(publish_topic), "CO2sensors/%s", sensorId);
+    snprintf(publish_topic, sizeof(publish_topic), "%s%s", config::mqtt_topic_prefix, sensorId);
 
     if (config::mqtt_encryption) {
       // The sensor doesn't check the fingerprint of the MQTT broker, because otherwise this fingerprint should be updated
@@ -62,11 +62,13 @@ namespace mqtt {
   void publish(const char *timestamp, int16_t co2, float temperature, float humidity) {
     if (wifi::connected() && mqttClient.connected()) {
       led_effects::onBoardLEDOn();
-      Serial.print(F("MQTT - Publishing message ... "));
+      Serial.print(F("MQTT - Publishing message to '"));
+      Serial.print(publish_topic);
+      Serial.print(F("' ... "));
 
       char payload[75]; // Should be enough for json...
       snprintf(payload, sizeof(payload), json_sensor_format, timestamp, co2, temperature, humidity);
-      // Topic is the same as clientID. e.g. 'CO2sensors/ESP3d03da'
+      // Topic is 'MQTT_TOPIC_PREFIX/ESP123456'
       if (mqttClient.publish(publish_topic, payload)) {
         Serial.println(F("OK"));
         ntp::getLocalTime(last_successful_publish);
@@ -130,7 +132,7 @@ namespace mqtt {
 
     if (connected) {
       if (config::allow_mqtt_commands) {
-        char control_topic[60]; // Should be enough for "CO2sensors/ESPd03cc5/control"
+        char control_topic[50]; // Should be enough for "MQTT_TOPIC_PREFIX/ESPd03cc5/control\0"
         snprintf(control_topic, sizeof(control_topic), "%s/control", publish_topic);
         mqttClient.subscribe(control_topic);
         mqttClient.setCallback(controlSensorCallback);
@@ -184,7 +186,7 @@ namespace mqtt {
   // If the sensor can be reach by MQTT, it can answer with info about local_ip and ssid.
   // The sensor will send the info to "CO2sensors/ESP123456/info".
   void sendInfoAboutLocalNetwork() {
-    char info_topic[60]; // Should be enough for "CO2sensors/ESP123456/info"
+    char info_topic[50]; // Should be enough for "MQTT_TOPIC_PREFIX/ESP123456/info"
     snprintf(info_topic, sizeof(info_topic), "%s/info", publish_topic);
 
     char payload[75]; // Should be enough for info json...

ampel-firmware/web_config.cpp

@@ -6,7 +6,7 @@
 #define STRINGIFY(x) STRING(x) // Allows to call STRINGIFY(SOME_MACRO) and convert the value of SOME_MACRO to string
 
 #include "config.h"
-#ifndef AMPEL_PASSWORD
+#ifndef MQTT_TOPIC_PREFIX
 #  error Missing config.h file. Please copy config.public.h to config.h.
 #  warning config.h has a new structure (e.g. AMPEL_WIFI should be set to true or false)
 #endif
@@ -118,6 +118,8 @@ namespace web_config {
   PasswordTParameter<STRING_LEN> mqttPasswordParam = Builder<PasswordTParameter<STRING_LEN>>("mqtt_password").label(
       "MQTT password").defaultValue(MQTT_PASSWORD).build();
 
+  TextTParameter<STRING_LEN> mqttTopicPrefixParam =
+      Builder<TextTParameter<STRING_LEN>>("mqtt_topic").label("MQTT Topic prefix").defaultValue(MQTT_TOPIC_PREFIX).build();
   /**
    * NTP Time
    */
@@ -204,6 +206,7 @@ namespace web_config {
     mqttParams.addItem(&mqttPortParam);
     mqttParams.addItem(&mqttUserParam);
     mqttParams.addItem(&mqttPasswordParam);
+    mqttParams.addItem(&mqttTopicPrefixParam);
     mqttParams.addItem(&mqttEncryptionParam);
     mqttParams.addItem(&mqttCommandsParam);
 
@@ -352,6 +355,7 @@ namespace config {
   char *mqtt_server = web_config::mqttServerParam.value();
   char *mqtt_user = web_config::mqttUserParam.value();
   char *mqtt_password = web_config::mqttPasswordParam.value();
+  char *mqtt_topic_prefix = web_config::mqttTopicPrefixParam.value();
   uint16_t &mqtt_port = web_config::mqttPortParam.value();
   uint16_t &mqtt_sending_interval = web_config::mqttIntervalParam.value();
   bool &mqtt_encryption = web_config::mqttEncryptionParam.value();

ampel-firmware/web_config.h

@@ -43,6 +43,7 @@ namespace config {
   extern char *mqtt_server;
   extern char *mqtt_user;
   extern char *mqtt_password;
+  extern char *mqtt_topic_prefix;
   extern uint16_t &mqtt_port;
   extern uint16_t &mqtt_sending_interval; // [s]
   extern bool &mqtt_encryption; // [true / false]