Hello

I have previously made a "garage door opener with webcam" using a Netgear ReadyNAS, the k8005() and a iPhone app.

I now want to replace it with the carambola instead (and package it for distribution), so my idea is to do the following:
1. Connect one of the GPIO pins to the garage door opener switch to open/close
2. Connect a webcam to the USB
3. Create a "registration" application with these steps:
3.1 The carambola will start with AP mode and the iPhone app should connect to the carambola
3.2 From the iPhone app select the home WIFI network so the carambola switches from AP to the home network
3.3 The carambola connects to a "Garage Door Opener Server" that I provide
4 The iPhone uses the "Garage Door Opener Server" to open/close the garage door

Feedback if my thinking is right is appreciated. I know this product isn't revolutionizing; I'm just doing it for fun.

For the application on carambola I'm thinking of using PHP and the mmio in order to toggle the GPIO pin, and the mjpg_streamer for the webcam. Any thoughts on that?

How will you make sure nobody else will get into your AP and "hack" your door ?
Just wondering!

I don't understand why your Carambola has to leave AP mode and connect to the house internal WiFi.
Isn't the Carambola the Garage Door opener Server? If not, why have a separate Server for that?

Also, once your Carambola leaves AP mode and connects to another WiFi network your iPhone will be disconnected.
If you need the connection to the "other WiFi" network, why not have the Carambola run in Client mode and let the iPhone connect directly to the internal network, where it communicates with your Garage Door Opener Server, which in turn tells the Carambola to open the Garage Door if authentication is successfull.
If the range of the WiFi network isn't enough to extend outside your garage you might think about using the Carambola as a WiFi Repeater to extend the range.

Ah now I finally get it. Running Carambola in AP mode ist just for the setup procedure, not for normal operations. Okay, that makes sense now.
OpenWRT already has a web interface for configuration, it's the Luci package, you might want to look into it and see if that could be adapted for your project.
You could of course still use PHP for that, but why reinvent the wheel, right?
I don't know if you'd really want SSL (read https) support. You'd need to generate a certificate by yourself, and browsers always complain about self signed certificates, which might confuse your customers into thinking your device is unsecure.
If you wanna go down that road though, there is an SSL library for Python, or you could just install an ordinary http server with SSL support and write your software in PHP.

Of course this is all just for the one time initial setup of the device (although you'd need a way -a hardware button for example- to put your Carambola back into setup mode. And as I said, once the Carambola switches from AP mode into client mode to connect to the other WiFi network your iPhone will be disconnected, so you'd need another way of indicating a successfull configuration).

Now the tricky part will be figuring out the communication method between Carambola and your online registration server. You'd certainly want that communication to be secure. So encryption is vital. You don't want open Ports on the Carambola that can be accessed through the internet (besides the fact that then your setup procedure would become more complex as it involves reconfiguring the existing router). So you're left with either polling the online server from the carambola in relatively short intervals, or keeping a TCP connection alive at all times. Either solution most likely involves setting up a Deamon Process to run in the background, because Cron Jobs only run every minute (not exactly true, but one minute is the smallest possible interval), and you don't want anyone to wait a minute before they can enter their garage.

Well, I'd chose Python for all these tasks, it can handle them well. But then again, I already know Python and what it's capable of.