Hello, I’m hoping that someone can provide me with a little bit of advise on the best way to progress. I have been using FreeRTOS on PIC32, which is bundled into Microchips Harmony Configuraiton engine. Its worked well for me once i got through the various hoops and learning. I’d now like to use some of the AWS FreeRTOS librarys ( MQQT and OTA ). When i looked at it,the project I discovered that they essnetially had been hand built ( at least the configuration ) for a specific platform. ( in my case the PIC32 Curosity board ). I have been able to upgrade FreeRTOS from version 9 to 10, and use it with Harmony no problme. ( i used the librarys from the AWS git repo ). I need/want to be able to take another PIC32 and differnet hardware and configure it ( ideally using harmony ), but the MQTT librarys require FreeRTOS + IP. Harmony of course does not know about how to deal with the freeRTOS stack. So, my choice is moving away from the Harmony IP stack ( and harmony ), which means loosing the ability to very quickly add / remove new perhials.. ( and also somethign we know very well ), to be able to use the MQTT library. ( but we would possibly loose some features in the microchip IP stack ).. Or I need to be able to figure out if i can modify the MQTT librarys to work with the Microchip Stack. I hope that my post made some sence.

The MQTT implementation includes an MQTT client library suitable for use in bare metal applications, and an MQTT agent for FreeRTOS. So you could integrate just the library, but it will be simpler to create an application if you could also integrate the agent. The agent (think daemon task) manages the MQTT library on behalf of the developer, providing the developer with a simple connect, publish, and subscribe interface, and unburdening the developer from having to do anything special to manage the MQTT protocol itself – for example there is no need to periodically call the MQTT library, the agent does that transparently in the background for you. As you point out, the agent has a couple of dependencies. Although the provided examples use the FreeRTOS+TCP stack, it does so through an abstraction layer (called the ‘secure sockets’ layer, as it also abstracts away TLS), so you could provide a port of that abstraction layer to the Harmony TCP/IP stack if you wanted to continue to use that stack. So you could update your project to use the FreeRTOS+TCP stack and the provided secure sockets abstraction layer for that stack, or you could update your project by providing your own secure sockets abstraction for the Harmony stack. Alternatively you could use just the MQTT library component. Let me know which way you think is best.

Thanks Richard, that really helped me get somethings sorted out in my head. In my way of thinking the best way forward ( at least for me ), would be to use Harmony and FreeRTOS 10.x ( which works nicely ). This gives me the best of all the worlds. the ‘cost’ to me is having to port the secure sockets layer. This does seem like the best way to move forward.

If you are not using TLS and the Harmony stack has a sockets like interface then there should be a fairly straight forward mapping to the secure sockets interface – you can just stub or not implement the TLS part. These are the components you will need from the Amazon FreeRTOS libraries – hope the formatting comes out ok: ~~~ Amazon FreeRTOS | +-lib | +-mqtt | +-awsmqttlib.c [Required to use library and agent] | +-awsmqttagent.c [Required to use the MQTT agent] | +-include | +-private [For internal library use only!] | +-awsdoublylinkedlist.h | +-awsmqttagentconfigdefaults.h | +-awsmqttbuffer.h | +-awsmqttconfigdefaults.h | +-awsmqttlibprivate.c | +-awsmqttconfigdefaults.h | +-awsmqttagent.h [Include to use the MQTT agent API] +-awsmqttlib.h [Include to use the MQTT library API] ~~~ You will also need configuration files that you can pull from the existing AWS examples: awsmqttlibconfig.h awsmqttagentconfig.h awsbufferpoolconfig.h awssecuresockets_config.h

Just formatted the snippet there so it fits better and realised I missed out that you need the buffer pool library too – which supplies buffers to the MQTT library.

Thanks, thats really helpful! using TLS will be required. Data has to transit the interweb!

Which TLS library are you using currently?

Not using any Library yet. Was thinking ( perhaps badly ) that i shoudl get it standing up without TLS first?

The Amazon examples are using mbedTLS, so you could pick that up too.

Thats handy. to know. Licencing is helpful as well. Hope to have the bones of a starting project soon.

In your list of files, Should awsmqttlibconfig.h actually be awsmqtt_config.h ? I can’t find a awsmqttlibconfig.h anywhere; the awsmqtt_config.h made the most sense to me.. Also, awsmqttlibprivate.c only seems to be related to some unit tests ( which are included if AMAZONFREERTOSENABLEUNIT_TESTS is defined. By adding this file to the project it causes errors ( as it has no includes for the .h file )? Is removing the file seems the best thign to do?

Apologies- you are correct on both counts.

Progress is being made; albeit a bit slowly.

• I’ve decided to go down this path as I to be sensible, i really need encryption ( TLS ) of the messages. there is a MQTT library ( WolfMQQT ) that is supplied with Harmony, but the moment that you use the Wolf Librarys you are into ‘interesting’ licencing territory that is largely incompatible with what I need/want to do.

Amazon uses mbedTLS, and that does not have the same license issues. Now work starts on porting the awssecuresockets to use the sockets that are used in Harmony. In order to make this an easy to use reference project, I am making modifications the the demo project that is supplied with Harmony 2.05.01 ( apps/rtos/freertos/tcpipclientserver). Work to date is at https://github.com/mrpackethead/harmonyawsfreertosmqtt Please NOTE this is NOT yet working. there is still work to be done! My project ends up at C:microchipharmonyv20501devrtosfreertosharmonyawsfreertos_mqtt In order to make this work a few things need to be installed; (1) The AWS Librarys. I have installed them at C:microchipharmonyv20501third_partyamazon-freertos The easiest way to get this is to clone it from Github, which has the most recent versions; https://github.com/aws/amazon-freertos Note that these librarys also include FreeRTOS, but it is the AWS Version which has been modified, and it is easier to use the generic FreeRTOS10.x (2) FreeRTOS 10.x; Harmony 2.05.01 ships with FreeRTOS9.x Fortunately upgrading it to Version 10.x is very simple. Download FreeRTOS from Source Forge ( https://sourceforge.net/projects/freertos/ ). Copy the Folder ‘FreeRTOS’ when its expanded out ( FreeRTOSv10.0.1FreeRTOS ) and use it to replace the FreeRTOS Folder that was installed with Harmony ( In my case it was C:microchipharmonyv20501third_partyrtosFreeRTOS )

I have removed awssecuresockets.c from my project, and created harmonysecuresockets.c