Doug Toppin's Blog

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AWS IoT and the MQTT.fx Client Updated

In the previous post I passed along a few tidbits about using the MQTT client with the AWS IoT service.

Since then both the AWS IoT service and the MQTT client have been updated. I decided to do an updated post with any new info. The AWS IoT configuration pages have noticeably changed.

The current MQTT client can be found at There are a few visible differences in the client configuration.

The IoT resources main panel now looks like this.

The certificate resource page now looks like this and the downloads will save as files that help with identifying which they are used for.

The cert names will appear something like these


In the previous post I had to replace newline characters in the cert files but this time I did not and was able to use them as is.

The MQTT client connection settings page will look something like this.

The root-cert can be found in the AWS IoT document here.

The pub/sub functions in the MQTT client worked without any trouble. The Log tab in the client can provide useful information if you run into any trouble. If there are any connection issues the cause should appear in the Log.