This post is part of the Temperature monitoring project.
The first choice to make was:
- Will the central site periodically polls all remote sites?
- Or will all the remote sites send their data to the central site?
Second option was taken. Advantages I see with this approach:
- No concern about internet security and server hacking (no incoming request from internet, so no firewall setup needed).
- No need to have as much fixed IP as we have places to monitor.
- If sending at a low pace, gives the possibility to shut off everything between sending (first idea was also to “record” locally and send later, but went short of RAM, and did not investigate external memory card).
However, as remote temp units are connected to network, a tiny (not to say pico) WEB server is embedded into the node to locally manage settings. But it is not intended at all to be accessed over internet.
Other choices to make:
- Remote unit hardware.
- Temp sensors hardware.
Further notes will detail that, but in a few words:
- Remote units will be built on ATMega microcontrollers on Arduino boards, and using an Ethernet Shield.
- Remote sensors will be both Arduino and commercial models.
- Central site is currently using www.pachube.com, but I started to implement corresponding stuff on this site, although it is not visible now.