These days more and more temperature sensor projects appear on the internet so the world must be in need of temperature sensors 
. Daniel got hi’s done and up on the blog. The project is based on the LM35 Precision Temperature Sensor and the Arduino. He also plans on building a temperature sensor with max/min + clock and LCD, he promisses to post it on the blog when its finished.
Arduino Temperature Sensor: [Link]
The EnvStick is cheap, homemade temperature sensor that plugs into a USB port. It provides a simple way to collect a room’s ambient temperature. Ned, the author made it purely for fun, so don’t expect too much from the project.
USB Temperature Sensor: [Link]
This project allows you to log temperature under 2 operating modes: Standalone, the system works standalone and can record a max of 2 temperatures or connected to a PC’s RS232 port thus having the ability to record up to 8 temperatures. The circuit is also interfaced with an LCD that can show 2 temperatures at the same time. It also has a separate DS1302 Real Time Clock (RTC) module with over 3 months backup and supports Wayne’s NTP format for updating the clock from an NTP server. The circuit is controlled by a Atmel AT90S2313, source code and schematics are provided.
LCD Temperature Monitor: [Link]
This is one of the smallest fan controllers I’ve seen. It does the same job as others, it controls the fan speed according to a temperature sensor. The main utility is that you save power this way, and second its noise reduction, the fan will now run most of the time at lower speeds. The whole circuit its based on 3 parts:
These are really easy to get parts, so you wont have any trouble. As a last word this is a very useful and simple to build project. Good luck building it.
Fan Temperature Controller: [Link]
A easy to install temperature monitor for cars and trucks running on veggie oil. Any veg oil used in a diesel engine needs to be heated to at least 160F (ideally more) to achieve a low viscosity. This device has three temperature sensors which can be zip tied to coolant or veggie oil hoses to indicate to the driver what the approximate temperature of the liquid inside is. The driver now has more information about the temperature of their veggie oil.
