Is MQTT the right protocol for this situation?

[Mark Butler]

Sorry for the stupid subject line. At least it's a little better than "Pleez send codes".

The plan is to put a tablet at the exit from a medical clinic to take a quick survey on how we did. (One question I hope) The survey tool is an existing internally developed web app. There is going to be a windows app running on the tablet to take a picture of the person taking the survey*. Basically, I need to trigger the camera on the tablet from the web server. 

I can modify the survey application to send a message when a survey starts or ends. Those events already exist. I'm developing the Windows app myself so I get to pick. 

For a proof of concept, and maybe even production, I can use IoT Hub on Azure. I'd like to use another MQTT server but I haven't been able to find one that is approved for our network. (Think enormous bureaucracy)

Our environment is Windows and .NET but I can get other servers stood up. (If I'm willing to take the pain) 

* We're going to send the image to the MS Cognitive Services Face API to get general emotion stuff and compare that to what they answered. https://azure.microsoft.com/en-us/services/cognitive-services/face/

Thanks,

MArk B.

[toast-uz]

I recommend that at the first you should consider using HTTP.

After you recognized the reason you could not use HTTP, you can consider others.

Because there are a lot of tools and tips on HTTP.

Regards,

Tatsuzo

[Mark Butler]

Okay, I did some research and see why you might suggest "http". As it turns out there could be hundreds of these kiosks and I detest constant polling. 

[toast-uz]

I agree the constant polling is difficult If you have thousands of tablets and wish realtime (<1s) control by the server.