analogReference(INTERNAL); Temp Sensor LMT86LP

So, after a long while of dealing with the LMT86LP Sensor, I've finally got it to work.
On to the next hurdle.
I want to use a servo motor which I'd like to change the analogReference to (INTERNAL). When i do this, my analog reading from the LMT86LP goes straight to 1023 with no variation.

What am I not seeing here.

ThunderBlade:
So, after a long while of dealing with the LMT86LP Sensor, I’ve finally got it to work.

How?
As I told you before, these sensors ideally want an Arduino with 2.56volt Aref.

Using them with 1.1volt Aref will restrict measuring range to 100-150C.

Tell us why you need 1.1volt Aref for a servo motor.
Leo…

I've looked back to the Data Sheet for this sensor and have found that the 1.1v Aref will be too low as the Supply Voltage should be between 2.2v and 5.5v. I get why this did not work now.

However, I don't see where there is any information about the Sensor that supports the 2.56v Aref that you listed in both this post and my first one regarding this sensor. The link that you provided on the other thread was not accurate to what the sensor is supposed to do.

As for the Servo Motor Aref...I saw some youtube video on the matter where they used this....I wrongly assumed that the motor needed this reference.

The main problem is sensor output voltage, not supply.

This sensor outputs a voltage between ~2.65volt (-50C) and ~0.4volt (150C).
See graph on page1 of the datasheet.

If you want to read that range with an Arduino, then Aref has to be at least the highest voltage that the sensor can produce. Even if you were happy with 0-50C, then you still would need a minimum Aref of ~2.1volt.

Default Aref (~5volt) won’t cut it for accurate temp measurements.
Any variation in Arduino’s supply voltage will have the same variation in temp.

If you don’t use the 3.3volt pin for anything else, then you could make a (reasonably) stable ~2.56volt Aref from that with a single resistor. Post your code if you want help with that.

Personally, I think it’s better to dump this sensor, and use an LM35 (~5c to 105C) or TMP36 (-45C to 55C) with 1.1volt Aref (if you want to stay analogue). Ultimately more accurate in combination with an Arduino.

A digital DS18B20 is even easier to use.
Leo…

I agree with you about dumping this sensor. I've ordered the LM35 and will give it a try. I was actually drawn to the LMT86 due to its accuracy, but it's proven to be sbit not of a pain.