anavi-thermometer-sw.ino: Reduce ClientID length

Reduce the ClientID length and try to keep it below 23 bytes. According to MQTT protocol version 5.0, the MQTT broker must allow 23 UTF-8 encoded bytes for ClientID. Some brokers MAY allow a longer ClientID: https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901059 This commit fixes GitHub issue #43: #43 Reported-by: Antonio Tapiador <[email protected]> Signed-off-by: Leon Anavi <[email protected]>
AnaviTechnology · Mar 22, 2020 · e900f4f · e900f4f
1 parent 3a479ec
commit e900f4f
Showing 1 changed file with 9 additions and 2 deletions.
diff --git a/anavi-thermometer-sw/anavi-thermometer-sw.ino b/anavi-thermometer-sw/anavi-thermometer-sw.ino
@@ -539,13 +539,20 @@ void MQTTStatus::publish_online(bool force_update)
 }
 
 MQTTConnection::MQTTConnection()
-    : espClient(), mqttClient(espClient), requested(false), status_list(0)
+    : espClient(), mqttClient(espClient), requested(false),
+      status_list(0), client_id(PRODUCT)
 {
 }
 
 void MQTTConnection::set_spec(const MQTTSpec *spec)
 {
-    client_id = String("anavi-thermometer-") + machineId + "-" + spec->topic;
+    String minId(machineId);
+    if (minId.length() > 5)
+    {
+      minId = minId.substring(minId.length() - 5);
+    }
+    client_id = String("anavi-") + minId + "-" + spec->topic;
+    Serial.println("set_spec client_id: " + client_id);
 }
 
 void MQTTConnection::connect()