Ethernet-based Temperature Sensor(s)

Wednesday, December 15, 2010 categories: electronics, sensors, side projects

This post is going to be a collection of links and information, to organize the information I gathered for a project. The goal of the project being to create a temperature monitoring system that could be setup and plugged into a network connection. Ideally then have that monitoring device be accessible over the Internet.

My initial information gather suggested that something like an Arduino + Ethernet Shield would be a good base device, or maybe a plug-style computer (like the SheevaPlug or Pogoplug). I also looked at the Netduino Plus briefly, and may look at it in the future.

Reasonably accurate temperature sensors are available as Dallas 1-wire bus devices, which seemed like a reasonable way to go since they can be read over RS-232 using a fairly simple circuit. There are also, apparently, 1-wire to USB bridge chips available (even supported in Linux). One such bridge is used in the LinkUSB, which is a convenient form factor that is supposed to work with long runs of twisted pair cable to connect the sensor, and abstracts the interface to an RS-232 based protocol. Dallas 1-wire seems to support the lengths of cable I would need.

I also looked quite a bit at RS-485. It would be another option, but I think there would be more implementation cost. The sensors that I saw were rather expensive. But FTDI offers convenient adapters for about the same cost as the LinkUSB. Looks like Sparkfun has some even cheaper!

I'll add another post if I ever execute this project.

Other references: