The Microcontroller Idea Book - Jan Axelson's Lakeview Research

Using Sensors to Detect and Measure
Figure 9-7. The LM385 series of voltage references includes 1.2V, 2.5V,
and an adjustable version.
Listing 9-3 assumes that an LM34 connects to CH2 on the ADC0848, and that VREF is 2.5V.
On request, it displays the current temperature.
For a smaller range, create a 1.2V reference with an LM385-1.2 and change line 70 in the
program to match. Another option is the LM385 adjustable reference, which contains a
reference diode and feedback amplifier. With the addition of a voltage source and resistors
in a voltage divider, you can set the LM385’s output to the reference voltage you need. Use
the formula shown to vary the resistors for different outputs.
Solar Energy
Figure 9-8 shows another sensor application, a solar cell that generates a current proportional
to the intensity of the light hitting the cell. The output of the solar cell in the example varies
The Microcontroller Idea Book 165