Enlarge the chunkSize

README.adoc

@@ -1,16 +1,52 @@
 // Define the repository information in these attributes
 :repository-owner: arduino-libraries
-:repository-name: MKRNB
+:repository-name: MKRNB SARA R410 MQTT Extension 0.1
 
 = {repository-name} Library for Arduino =
 
-image:https://github.com/{repository-owner}/{repository-name}/workflows/Compile%20Examples/badge.svg["Compile Examples Status", link="https://github.com/{repository-owner}/{repository-name}/actions?workflow=Compile+Examples"]
-image:https://github.com/{repository-owner}/{repository-name}/workflows/Spell%20Check/badge.svg["Spell Check Status", link="https://github.com/{repository-owner}/{repository-name}/actions?workflow=Spell+Check"]
 
-This library enables an Arduino MKR NB 1500 board to connect to the internet over a NarrowBand IoT or LTE Cat M1 network. 
+This library enables an Arduino MKR NB 1500 board to connect to the internet over a NarrowBand IoT or LTE Cat M1 network.
+The Cpt. Holzschnauz extension makes it possible to use the internal MQTT functionality of the SARA R410 modem for convenient MQTT.
 
-For more information about this library please visit us at
-https://www.arduino.cc/en/Reference/{repository-name}
+MQTT without external mqtt libraries, tcp socket headaches etc. Easy & convenient! Let the modem do the sh..!
+
+
+UNDER CONSTRUCTION!! BETA! NOT FINISHED! CONTRIBUTE IF YOU CAN! Check the example.
+
+
+
+Done:
+Constructor: Example: NBMqtt mqtt;
+
+getMQTTerror Get the last MQTT error from the modem.Example: mqtt.getMQTTerror();  
+
+setMQTTClientID  Set the MQTT client ID : Use your SIM IMEI. Example: mqtt.setMQTTClientID("352753090834234");  
+
+setMQTTPort(Int): Set the MQTT Port (Normaly not enrcypted is 1883, SSL is 8883. Example:  mqtt.setMQTTPort(1883);  
+
+setMQTTUserPassword(String, String): Set Username / Password for the MQTT broker. Example: mqtt.setMQTTUserPassword("username", "password");  
+
+setMQTTbrokerURL(String): Set the MQTT broker URL (DNS is made automatic). Example: mqtt.setMQTTBrokerURL("public.cloud.shiftr.io");   
+
+setMQTTbrokerIP(String): Set the MQTT broker IP (not necessary in general, provide a broker URL!) Example: setMQTTbrokerIP(84.15.13.144);
+
+setMQTTBrokerConnect(bool): Connect / Disconnect to the MQTT broker. Example: mqtt.setMQTTBrokerConnect(true); to connect, mqtt.setMQTTBrokerConnect(false); to disconnect  
+
+sendMQTTMsg(String, String): Send a MQTT message to a topic. Example: mqtt.sendMQTTMsg("/TestTopic", "TestMessage");  
+
+setMQTTSubscribe(String): Subscribe to a topic. Example: setMQTTSubscribe("TestTopic");  
+
+To do:  
+
+Read out MQTT messages  
+
+Set Timeouts  
+
+Set last will  
+
+Save/restore settings to NV memory
+
+SSL
 
 == License ==
 

examples/SARA_NBMQTT_Example.ino

@@ -0,0 +1,95 @@
+/*
+  MQTT Client class extension for the MKRNB lib. Use the internal MQTT stack of the SARA R410 modem to do MQTT without a library, creating sockets etc. Easy & convenient!
+
+  This sketch, for the MKR NB 1500 board, setup a MQTT connection and send a MQTT Message 
+  Circuit:
+   MKR NB 1500 board
+   Antenna
+   SIM card 
+
+  created August 4th 2021
+  Version 0.1 by Roman Bolt
+
+Done:
+
+Constructor: Example: NBMqtt mqtt;
+
+getMQTTerror Get the last MQTT error from the modem.Example : mqtt.getMQTTerror();
+setMQTTClientID  Set the MQTT client ID : Use your SIM IMEI. Example mqtt.setMQTTClientID("352753090834234");
+setMQTTPort(Int): Set the MQTT Port (Normal is 1883, SSL is 8883(not yet implemented). Example :  mqtt.setMQTTPort(1883);
+setMQTTUserPassword(String, String): Set Username / Password for the MQTT broker. Example: mqtt.setMQTTUserPassword("username", "password"); 
+setMQTTbrokerURL(String): Set the MQTT broker URL (DNS is made automatic). Example: mqtt.setMQTTBrokerURL("public.cloud.shiftr.io"); 
+setMQTTbrokerIP(String): Set the MQTT broker IP (not necessary in general, provide a broker URL!)
+setMQTTBrokerConnect(bool): Connect / Disconnect to the MQTT broker. Example: mqtt.setMQTTBrokerConnect(true); to connect, mqtt.setMQTTBrokerConnect(false); to disconnect
+sendMQTTMsg(String, String): Send a MQTT message to a topic. Example: mqtt.sendMQTTMsg("/TestTopic", "TestMessage");
+setMQTTSubscribe(String): Subscribe to a topic. Example: setMQTTSubscribe("TestTopic");
+
+To do:
+
+Read out MQTT messages
+Set Timeouts
+Set last will
+Save/restore settings
+
+*/
+
+// include the NB library
+#include <MKRNB.h>
+
+// Please enter your sensitive data in the Secret tab or arduino_secrets.h
+// PIN Number
+const char PINNUMBER[] = "";
+
+// initialize the library instances
+NB nbAccess(true);
+NBScanner scannerNetworks;
+NBMqtt mqtt;
+
+void setup() {
+  // initialize serial communications and wait for port to open:
+  Serial.begin(115200);
+  while (!Serial) {
+    ; // wait for serial port to connect. Needed for native USB port only
+  }
+
+  Serial.println("SARA MQTT Test");
+
+  // connection state
+  bool connected = false;
+
+  // Start GSM connection
+
+  while (!connected) {
+    if (nbAccess.begin(PINNUMBER) == NB_READY) {
+      connected = true;
+    } else {
+      Serial.println("Not connected");
+      delay(1000);
+    }
+  }
+
+  Serial.println("NB initialized");
+
+  mqtt.setMQTTClientID("352753090834234"); // Set Client ID : USE your SIM's UMEI
+  mqtt.setMQTTPort(1883);//Set mqtt Port
+  mqtt.setMQTTBrokerURL("public.cloud.shiftr.io"); 
+  mqtt.setMQTTUserPassword("public", "public"); // User, Password
+  mqtt.setMQTTBrokerConnect(true);
+
+}
+
+void loop() {
+
+mqtt.sendMQTTMsg("/TestTopic", "TestMessage");
+// A little hint: If you want to construct the MQTT message out of Strings and other variables, use: 
+// char* mqtt_msg = foo bar etc.
+// mqtt.sendMQTTMsg("/TestTopic", mqtt_msg);  
+
+String mqtt_error = mqtt.getMQTTerror();
+Serial.print("MQTT Error (See page 408 of the u-blox AT Manual): ");
+Serial.println(mqtt_error);
+
+delay(5000);
+Serial.println("Done");
+
+}

keywords.txt

@@ -46,6 +46,15 @@ hostByName	KEYWORD2
 getTime	KEYWORD2
 setTime	KEYWORD2
 getLocalTime	KEYWORD2
+getMQTTerror KEYWORD2
+setMQTTClientID KEYWORD2
+setMQTTPort KEYWORD2
+setMQTTUserPassword KEYWORD2
+setMQTTbrokerURL KEYWORD2
+setMQTTbrokerIP KEYWORD2
+setMQTTBrokerConnect KEYWORD2
+sendMQTTMsg KEYWORD2
+setMQTTSubscribe KEYWORD2
 
 #######################################
 # Constants

src/MKRNB.h

@@ -32,5 +32,5 @@
 #include "NBUdp.h"
 
 #include "NBFileUtils.h"
-
+#include "NBMqtt.h"
 #endif

src/NBClient.cpp

@@ -285,13 +285,13 @@ size_t NBClient::write(const uint8_t* buf, size_t size)
   size_t written = 0;
   String command;
 
-  command.reserve(19 + (size > 256 ? 256 : size) * 2);
+  command.reserve(19 + (size > 512 ? 512 : size) * 2);
 
   while (size) {
     size_t chunkSize = size;
 
-    if (chunkSize > 256) {
-      chunkSize = 256;
+    if (chunkSize > 512) {
+      chunkSize = 512;
     }
 
     command.reserve(19 + chunkSize * 2);
@@ -455,4 +455,4 @@ void NBClient::handleUrc(const String& urc)
       }
     }
   }
-}
+}

src/NBMqtt.cpp

@@ -0,0 +1,102 @@
+/*
+TO DO
+AT+UMQTT 0
+AT+UMQTT 1
+AT+UMQTT 2
+
+AT+UMQTT 4
+AT+UMQTTC=1
+AT+UMQTTC=2
+
+
+*/
+#include "Modem.h"
+
+#include "NBMqtt.h"
+
+NBMqtt::NBMqtt(bool trace)
+{
+  if (trace)
+  {
+    MODEM.debug();
+  }
+}
+
+String NBMqtt::getMQTTerror()
+{
+  String response;
+
+  MODEM.send("AT+UMQTTER");
+  if (MODEM.waitForResponse(1000, &response) == 1)
+  {
+    int firstSpaceIndex = response.indexOf(' ');
+    int lastCommaIndex = response.lastIndexOf(',');
+
+    if (firstSpaceIndex != -1 && lastCommaIndex != -1)
+    {
+      return response.substring(firstSpaceIndex + 1, lastCommaIndex);
+    }
+  }
+
+  return "";
+}
+
+String NBMqtt::setMQTTClientID(char *mqttID)
+{
+  MODEM.sendf("AT+UMQTT=0,\"%s\"", mqttID);
+  MODEM.waitForResponse(10000);
+  return "";
+}
+
+int NBMqtt::setMQTTPort(int mqttPort)
+{
+  MODEM.sendf("AT+UMQTT=1,%d", mqttPort);
+  MODEM.waitForResponse(10000);
+  return 0;
+}
+
+String NBMqtt::setMQTTUserPassword(char *mqttUser, char *mqttPW)
+{
+  MODEM.sendf("AT+UMQTT=4,\"%s\",\"%s\"", mqttUser, mqttPW);
+  MODEM.waitForResponse(10000);
+  return "";
+}
+
+String NBMqtt::setMQTTBrokerURL(char *brokerURL)
+{
+  MODEM.sendf("AT+UMQTT=2,\"%s\"", brokerURL);
+  MODEM.waitForResponse(10000);
+  return "";
+}
+
+String NBMqtt::setMQTTBrokerIP(char *brokerIP)
+{
+  MODEM.sendf("AT+UMQTT=3,\"%s\"", brokerIP);
+  MODEM.waitForResponse(10000);
+  return "";
+}
+
+bool NBMqtt::setMQTTBrokerConnect(bool con)
+{
+  if (con == true)
+  {MODEM.sendf("AT+UMQTTC=1");}
+  if (con == false)
+    {MODEM.sendf("AT+UMQTTC=0");}
+
+  MODEM.waitForResponse(10000);
+  return "";
+}
+
+String NBMqtt::sendMQTTMsg(char *mqttTopic, char *mqttMsg)
+{
+  MODEM.sendf("AT+UMQTTC=2,0,0,\"%s\",\"%s\"", mqttTopic, mqttMsg);
+  MODEM.waitForResponse(10000);
+  return "";
+}
+
+String NBMqtt::setMQTTSubscribe(char *sub_topic)
+{
+  MODEM.sendf("AT+UMQTTC=4,0,\"%s\"", sub_topic);
+  MODEM.waitForResponse(10000);
+  return "";
+}

src/NBMqtt.h

@@ -0,0 +1,65 @@
+
+
+#ifndef _NB_MQTT_H_INCLUDED
+#define _NB_MQTT_H_INCLUDED
+
+#include "NB.h"
+
+class NBMqtt
+{
+
+public:
+  /** Constructor
+      @param trace    if true, dumps all AT dialogue to Serial
+      @return - 
+  */
+  NBMqtt(bool trace = false);
+
+  /** Obtain MQTT Error
+      @return MQTT Error
+   */
+  String getMQTTerror();
+
+  /** Set MQTT ClientID
+      @return -
+   */
+  String setMQTTClientID(char *mqttID);
+
+  /** Set MQTT Port Number
+      @return -
+   */
+  int setMQTTPort(int mqttPort);
+
+  /** Set MQTT Username Password
+      @return -
+   */
+  String setMQTTUserPassword(char *mqttUser, char *mqttPW);
+
+  /** Set MQTT Broker URL
+      @return -
+   */
+  String setMQTTBrokerURL(char *brokerURL);
+
+  /** Set MQTT Broker IP
+      @return -
+   */
+  String setMQTTBrokerIP(char *brokerIP);
+
+ /** Connect / Disconnect MQTT Broker
+      @return -
+   */
+  bool setMQTTBrokerConnect(bool con);
+
+   /** Send a MQTT Message
+      @return -
+   */
+  String sendMQTTMsg(char *mqttTopic, char *mqttMsg);
+
+/** Subscribe to a Topic
+      @return -
+   */
+  String setMQTTSubscribe(char *sub_topic);
+
+};
+
+#endif