I have an LM35 with an input, output and ground pinout.
The input will be 5V, the analog output signal will be processed by the Arduino (0-1024).
Instead of using the 5V reference, I want a higher resolution, so I'm using the internal 1.1V reference instead.
However, I have noticed that the on-board 5V regulator doesn't always produce 5V (or even 4.980).. I have 4 boards and the regulation is not too good.
So, in light of that, I fixed an L7805CV 5V regulator with a 0.347uF on the 12V input going to ground, and a 0.1uF cap on the output. (the datasheet says 0.33uF on the input, but I didn't have that or an equivalent network to produce it.)
If I supply the LM35 sensor with this new regulated 5V, will I be able to use the 1.1V internal reference on the Arduino (given the regulation network and LM35 both are wired to the Arduino ground) ?
Is that how the 1.1V reference works? Or is it based on the Arduino-regulated 5V?