Kinetis MicrocontrollersのトピックRe: MQTT using domain name

MQTT using domain name

jakarman12 — Mon, 23 Apr 2018 21:02:42 GMT

Hi guys,

I'm learning MQTT and I'm following BlackNight example.

MQTT Example

Is there an example of how to connect using the domain name of the MQTT broker?

This is because the IP of the broker I am using is dynamic.

Regards

Jordan García

Re: MQTT using domain name

mjbcswitzerland — Tue, 24 Apr 2018 20:21:39 GMT

Hi Jordan

There is another MQTT implementation described here that you could also try - it is also open source: https://community.nxp.com/message/994806 but allows you to run on any Kinetis part and also in its Kinetis simulator for easier analysis and testing.
Documentation: http://www.utasker.com/docs/uTasker/uTasker_MQTT.pdf
Video: https://youtu.be/-_CV2aXHyjw

The DNS part is a separate process that is performed before starting the connection. It can be done as following in the uTasker implementation (example of connecting to "test.mosquitto.org"):

fnResolveHostName("test.mosquitto.org", fnDNSListner);                   // resolve broker's address

static void fnDNSListner(unsigned char ucEvent, unsigned char *ptrIP)    // called when DNS resolution has completed
{
    unsigned char ucBroker[IPV4_LENGTH];
    switch (ucEvent) {
    case DNS_EVENT_SUCCESS:                                              // the address has been successfully resolved
        uMemcpy(ucBroker, ptrIP, IPV4_LENGTH);                           // save the IP address which has just been resolved
        fnConnectMQTT(ucBroker, fnMQTT_callback, (UNSECURE_MQTT_CONNECTION | MQTT_CONNECT_FLAG_CLEAN_SESSION)); // establish MQTT connection
        break;
    default:                                                             // DNS error message
        break;
    }
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Regards

Mark

Kinetis: http://www.utasker.com/kinetis.html

Free Open Source solution: https://github.com/uTasker/uTasker-Kinetis
Working project in 15 minutes video: https://youtu.be/K8ScSgpgQ6M

For better, faster, cheaper product developments consider the uTasker developer's version, professional Kinetis support, one-on-one training and complete fast-track project solutions to set you apart from the herd : http://www.utasker.com/support.html

Re: MQTT using domain name

jakarman12 — Tue, 24 Apr 2018 22:33:43 GMT

Hello Mark,

Do you have a complete example that you can modify?

If I need TLS, does it cost?

Regards

Re: MQTT using domain name

mjbcswitzerland — Wed, 25 Apr 2018 00:27:57 GMT

Hi Jordan

There is a command line interface application as described in the manual and I also added code to allow publishing data received from an nRF24L01 radio connection as described here
https://community.nxp.com/message/999272?commentID=999272#comment-999272

Presently I have offered the MQTT implementation to the open source community but MQTTS (TLS) is presently reserved for licensees (who finance several months of development to be able to realise the quality required) who then have personal support.

Otherwise you could use Amazon FreeRTOS (where there is an MQTT/TLS application) since you may be able to port it to a Kinetis with a few days work, depending on your experience. I think that Eric also has something working with mbedTLS if you prefer that route.

Regards

Mark

uTasker developer and supporter (+5'000 hours experience on +60 Kinetis derivatives in +80 product developments)
Kinetis: http://www.utasker.com/kinetis.html

Re: MQTT using domain name

danielchen — Wed, 25 Apr 2018 05:12:26 GMT

Hi Jordan:

Just an information that MQX 5 supports MQTT and REST. But it is under commercial licensing terms.

MQX™ v5 Software Solutions|NXP

Regards

Daniel