I am a beginner in working with the Arduino but I always had the intention to create applications with a microcontroller. And now it's time to start with it ...
During the last days I bought books about the subject and was travelling around the internet.
I think that I need some help in the beginning or inspiration how I should realize my first idea.
I would like to install several sensors (temperature, humidity, air pressure) inside and outside of my home. I would like to look up the current values whenever I want to via w-lan/Internet.
And of course I am looking for an possibility to save the data regularly.
Which hardware should I use and how should I build the project?
I'd look for a solution where each sensor transmitted data back to a PC at regular intervals, and use a database and web app to store and publish it from there.
There are a variety of wireless options to transmit the data back to the PC. nRF24L01+ transceivers are probably the cheapest option but you would need to find out whether they provide sufficient range for your project. (I found that they are pretty good while there is a direct line-of-sight but they don't cope well with walls/floors so I ended up making a store/forward mesh network. There are other types of wireless network with much greater range but they are likely to cost more.)
Have you thought about just using an arduino with an Ethernet/wifi shield. Try have an sd card slot for data logging. You can start a small web server and read the data from the sd card
I've heard people transmitting data from xbee modules from the computer and the arduino. If the pc is necessary. I do assume an ad card can log a huge amount of text data for a standalone arduino.