TMP36 temperature probe

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi,

Im trying to make a thermostat system for a reptile enclosure using a number of TMP36 temperature sensors. At the moment they are on my breadboard working quite happily but i want to turn them into probes on the end of 1-2 meters of cable.

I have very little knowledge of cables but have heard that using the wrong ones can lead to poor signal strength and bad results so i was just wondering what would be best to use?

I found an instructable showing some guy making a water proof probe (cant post a link as this is my first post and it wont let me lol) and he is using Cat-5 but it seems his choice is based on him having a large supply of it. Would this be the best or would there be another option? Also, would i need to add an extra resistor to the Vout. At the moment there isnt one.

I would also like to give the sensor some degree of protection. It doesn't have to be completely water proof so i was thinking of using some heat shrink wrapped around the end. Im guessing this would effect the reading though as it would be insulating it in some way.

2

Im guessing this would effect the reading though as it would be insulating it in some way.

Insulation doesn't affect the reading as such, just the lag from a change in temp to reading that change. As I doubt you're too worried about response time this shouldn't matter.

Whatever PID-style code you set up will have to allow for lag anyway.

Rob

3

Cheers for the reply.

Yeah the response time doesn't really mater as long as its not too long. I guess i can measure the time difference using insulated and non insulated sensors and write it into the code.

Anyone got any ideas about the cable issue?