demo runner: demos try to use BLE as MQTT transport even if IOT_BLE_ENABLE_MQTT == 0

[matteoscordino]

Describe the bug It seems that if the define BLE_ENABLED is true, demos will try to use a BLE connection as an MQTT proxy regardless of whether IOT_BLE_ENABLE_MQTT is enabled. In other words, there is the assumption that a BLE connection will always have on the other end an app that uses the AWS Mobile SDK to provide an MQTT proxy. This is not true if we want to run the BLE Wifi Provisioning demo without the MQTT proxy. It is also a problem if in your device you only want to use BLE for WiFI provisioning, and then have NetworkManager handle the wifi connection (which is my use case) Of course, I might have misunderstood the meaning of the defines in question, but in my use case this seems to be an issue.

System information

• Which hardware board or part numbers? ESP32
• IDE used: CLion, CMake
• Operating System Linux host
• Version of Amazon FreeRTOS: master
• Project: Custom Application, MQTT

Expected behavior

• Enabling BLE as a network
• but disabling MQTT over BLE
• and enabling BLE Wifi Provisioning should result in the application initialising the BLE services, but then not starting the demo task until a wifi network is available

To reproduce Steps to reproduce the behavior:

1. set #define configENABLED_NETWORKS ( AWSIOT_NETWORK_TYPE_WIFI | AWSIOT_NETWORK_TYPE_BLE ) in aws_iot_network_config.h
2. set #define IOT_BLE_ENABLE_MQTT (0) in iot_ble_config.h
3. set #define IOT_BLE_ENABLE_WIFI_PROVISIONING ( 1 ) in iot_ble_config.h
4. run the MQTT demo
5. connect to the device with a BLE Central (no need to use an AWS demo, Lightblue is enough)
6. the demo will start immediately and try to use BLE as a network

Additional context As a fix I have wrapped certain parts of iot_demo_freertos.c in #if BLE_ENABLED && (IOT_BLE_ENABLE_MQTT == 1) checks. I can create a PR if this is considered valuable and I have not misunderstood the meaning of the defines in question Thank you!

[tgsong]

Hi,

Thanks for reporting the issue. Our doxygen comment was not correct about IOT_BLE_ENABLE_MQTT, it was for BLE data transfer service, not for setting which connection type to use in MQTT. So to clarify,

• configENABLED_NETWORKS in aws_iot_network_config.h controls which module is being built, and initialized in demos. So if you set it to ( AWSIOT_NETWORK_TYPE_WIFI | AWSIOT_NETWORK_TYPE_BLE ), then both WiFi and BLE will be built and initialized.
  • For BLE, the device will start advertisement and wait for a connection.
  • For WiFi, if IOT_BLE_ENABLE_WIFI_PROVISIONING is 0, then WiFi credentials in aws_clientcredential.h will be used. If IOT_BLE_ENABLE_WIFI_PROVISIONING is 1, then WiFi will be provisioned through BLE and the mobile app.
• democonfigNETWORK_TYPES in aws_demo_config.h controls which transportation layer is used for MQTT. If democonfigNETWORK_TYPES is set to AWSIOT_NETWORK_TYPE_WIFI | AWSIOT_NETWORK_TYPE_BLE, then the first connection available will used for MQTT. Based on the first point, if you want to provision WiFi through BLE, BLE will be connected first, and WiFi will be waiting until it's provisioned through the app, so in this case BLE will be used in MQTT.

So, if you intention is to do WiFi provisioning through BLE, then use WiFi for MQTT,

1. set #define configENABLED_NETWORKS ( AWSIOT_NETWORK_TYPE_WIFI | AWSIOT_NETWORK_TYPE_BLE ) in aws_iot_network_config.h
2. set #define democonfigNETWORK_TYPES ( AWSIOT_NETWORK_TYPE_WIFI ) in aws_demo_config.h (Make sure it's set in the #if defined( CONFIG_MQTT_DEMO_ENABLED ) section)

[matteoscordino]

Thank you Tiangang,

that is exactly what I needed to achieve, and indeed it was all about understanding the intended usage of those configuration macros. I guess the related PR #1283 is not needed, I'll go ahead and close it.

[gordonwang0]

Hi @matteoscordino,

Please let us know if you have any further questions. Closing issue.