MCU8MASS-2370 Add keep alive argument to AWS and Azure for low power applications

Author: M65649

examples/mqtt_low_power/mqtt_low_power.ino

@@ -13,7 +13,7 @@
 #include <mqtt_client.h>
 #include <veml3328.h>
 
-#define USE_PSM false
+#define USE_PSM true
 
 static char mqtt_pub_topic[128];
 
@@ -56,7 +56,7 @@ void setup() {
 #if USE_PSM
     LowPower.configurePeriodicPowerSave(
         PowerSaveModePeriodMultiplier::ONE_MINUTE,
-        1);
+        3);
 #else
     LowPower.configurePowerDown();
 #endif
@@ -65,8 +65,11 @@ void setup() {
 
     // If we're using PSM, we only need to connect to the MQTT broker at the
     // beginning, since the connection will remain active
+    //
+    // Here we also set the keep alive to 3 minutes to match the sleep period
+    // for PSM
 #if USE_PSM
-    MqttClient.beginAWS();
+    MqttClient.beginAWS(180);
 #endif
 
     Mcp9808.begin();

src/mqtt_client.cpp

@@ -261,7 +261,7 @@ static bool generateSigningCommand(char* data, char* command_buffer) {
     return true;
 }
 
-bool MqttClientClass::beginAWS() {
+bool MqttClientClass::beginAWS(const uint16_t keep_alive) {
 
     ATCA_STATUS status = ECC608.begin();
 
@@ -312,13 +312,13 @@ bool MqttClientClass::beginAWS() {
                        (char*)(endpoint),
                        8883,
                        true,
-                       60,
+                       keep_alive,
                        true,
                        "",
                        "");
 }
 
-bool MqttClientClass::beginAzure() {
+bool MqttClientClass::beginAzure(const uint16_t keep_alive) {
 
     ATCA_STATUS status = ECC608.begin();
 
@@ -379,14 +379,21 @@ bool MqttClientClass::beginAzure() {
                hostname,
                device_id);
 
-    return this->begin(device_id, hostname, 8883, true, 60, true, username, "");
+    return this->begin(device_id,
+                       hostname,
+                       8883,
+                       true,
+                       keep_alive,
+                       true,
+                       username,
+                       "");
 }
 
 bool MqttClientClass::begin(const char* client_id,
                             const char* host,
                             const uint16_t port,
                             const bool use_tls,
-                            const size_t keep_alive,
+                            const uint16_t keep_alive,
                             const bool use_ecc,
                             const char* username,
                             const char* password,

src/mqtt_client.h

@@ -57,7 +57,7 @@ class MqttClientClass {
                const char* host,
                const uint16_t port,
                const bool use_tls,
-               const size_t keep_alive   = 60,
+               const uint16_t keep_alive = 1200,
                const bool use_ecc        = true,
                const char* username      = "",
                const char* password      = "",
@@ -67,12 +67,12 @@ class MqttClientClass {
     /**
      * @brief Will configure and connect to the provisioned AWS broker.
      */
-    bool beginAWS();
+    bool beginAWS(const uint16_t keep_alive = 1200);
 
     /**
      * @brief Will configure and connect to the provisioned Azure broker.
      */
-    bool beginAzure();
+    bool beginAzure(const uint16_t keep_alive = 1200);
 
     /**
      * @brief Disconnects from the broker and resets the state in the MQTT