The sensor

I've chosen a digital sensor in order to avoid A/D conversion and non-linear responses; the digital sensor performs the A/D conversion in-situ and implements the communication protocol to inform about the measurement. I've used the Maxim parametric search for temperature sensors for choosing the right one. I've decided to use the DS18S20 because:

• Has a reasonable accuracy of 0,5ºC
• The package is a TO-92 which fits fine at the places I want to install them without using a pcb
• Implements 1-wire communication protocol

DS18S20 digital sensor

The begining

Hi, some time ago I though it would be a good idea to monitor the temperature of every room at home. I have a very bad HVAC installation because temperature sensors always read almost the same temperature (around 28ºC) and the air is too cold or too hot. The brand of the HVAC equipment is very popular but I am not going to say its name, I am pretty upset with both the equipment and the company who made the installation. Anyway that's not the topic of this blog. The idea (just for fun) is to install a network of sensors capable of reading true temperature of every room and transmit them to my main PC. It will be achieve using several 1-wire DS18S20 temperature sensors from Dallas Semiconductor and a microcontroller from Atmel. The progress of my project will be shown here.