MLX90614

what is the difference in capabilities of 3v vs the 5v version of the ir temperature sensor. I am trying to take the temperature of a car tire in three places of the tire (inside , middle , outside) i plan on using this model to make my project http://wiki.wiring.co/wiki/Connecting_Infrared_Thermometer_MLX90614_to_Wiring

Best Regards Cory

what is the difference in capabilities of 3v vs the 5v version of the ir temperature sensor.

The 5V version uses more power (up to 10mW compared to up to 6mW). And there is no 5V version with medical accuracy.

i plan on using this model to make my project

Which model, the MLX90614 is a sensor family. Have you tried if the sensor is able to get the temperature of a fast moving object? I haven't. I don't see a reason why it shouldn't but you may have to think about it and probably try it before you buy three of the sensors.

in model I mean I am going to use this guide

http://wiki.wiring.co/wiki/Connecting_Infrared_Thermometer_MLX90614_to_Wiring

to complete my project I have spoken with alot of the guys around the auto shop and they say they use the MLX90614 esf-AAA to do the same thing

The ESF-AAA version is limited at 85°C, my tires don't get that hot but I guess your doing races and I have no clue how hot tires get under such conditions. Your biggest problem is probably how to keep the sensors clean during the drive. One drop of dirt on the sensor and your won't get realistic data anymore.

I was planning on printing a housing for the sensors in which they will gaurd against the dirt and grime of a race track. I am struggling right now to find a diagram on how to hook the sensor to the digital input, im hooking up 12 sensors and I was told it would be easyer to use the digital input and use pwm.

You'll find a good description of how to connect the sensor to your Arduino on this page:

http://publiclaboratory.org/notes/ad/11-28-2011/thermal-camera-arduino-uno-mlx90614-ir-thermometer

Just keep in mind that you must have the pull-ups only once per bus.

The MLX90614 has a completely configurable bus address so theoretically you can connect up to 127 sensors to one bus. In your case I think the bus length will be more of a problem (it shouldn't exceed a length of about half a meter).

If it's easier to use the PWM data depends a lot on your needs and wiring. The PWM data is easier to transport over longer wires but the precision is lower. The read-out frequency is also potentially much lower than when using the SMbus interface.