I have been searching the web for a while trying to find some direction on how to proceed with a project I am working on.
I have an arduino board with ethernet shield (webserver) reading temperature data and logging it to an SD card. The Ethernet shield is connected to a wifi router using an RJ45 cable. The wifi router is used to create a local wifi network so someone in the area with a mobile device (android, iphone, tablet, laptop,etc.) can connect to the network and access the Arduino webserver.
This whole setup is in a remote location with no cell coverage or internet access.
The user can use a mobile wifi device with a browser to access the Arduino webserver and see current temperatures. They can also go to webpages to calibrate the sensors and change other settings like logging frequency.
Another feature I need to add is the ability to download the log files from the SD card through the HTML interface. I am working on that now and have found lots of examples.
It is not ideal to have someone remove the SD card to get the data. Thus the use of a wifi network.
Where I need help is the next step: How can I graph data in HTML so that the user can see historical temperatures on their device?
I have also found examples of installing DD-WRT firmware on the router and then using the router to host .css and .js files. I really would like to avoid modifying the router firmware, unless that is the best option.
I need some direction, or a reality check to let me know this can not be done with just an Arduino, Ethernet Shield and a wifi router.