Summary: The following is a step by step guide on how to make a Heat-Seeking Desk Fan from an Arduino microcontroller, a computer fan, a servo, and an infrared temperature sensor. The device scans the room periodically, automatically pointing itself in the hottest direction (ideally towards a person). This is a working proof-of-concept model, but it could be easily scaled up should the investment seem worthwhile.
I built this as a project for a college electronics course and had originally planned to include a clap sensor to activate the scan, but didn't have enough time or money. I'll provide an update should I decide to add it in the future.
The concept, design, and code is mine, except for the temp sensor communication code submitted by Sensorjunkie.
Cost: $70 (including Arduino Uno)
Difficulty: Basic Arduino experience is essential. Some of the electronics are not easy to troubleshoot should you run into problems.
Step 1: Materials
Summary: The required stuff. I've provided links for all the specific parts which cannot be substituted. Everything else you're free to pull from anywhere. Seriously, get creative. Your options will be more clear as you continue reading.
-- Infrared Thermometer MLX90614
-- Large Servo Motor
-- Arduino Uno Microcontroller
-- Computer Fan 12V DC
-- 12V DC Transformer
-- Through-hole circuit board
-- Baseplate (6x8in material of your choosing)
-- Nuts and Bolts
-- Various Adhesives
-- Soldering Iron
-- Hot Glue Gun
-- Drill Press