Temperature sensor devices are common around us. They differ in their precision and measuring method. What interests us is MCU based temperature meter that gives reliable readings. For instance cheap room thermometers aren’t that precise. They can be have error about 1 degree. This might not be acceptable in some situations. So what to do if you want really precise measurements? Scott Harden has been working on new projects where he wants to control crystal oven with high precision. As sensor he chooses LM335 linear temperature sensor. In order to get high resolution, he built LM324 op-amp based based circuit which expands smaller temperature interval to Atmega8 microcontroller ADC range and thus he gets about 0.01F resolution.
Since he uses cheap and available components like LM324 operation amplifier, this project becomes really attractive. You can get crisp temperature controller without investing much. As this is initial project stage, Scott plots data using Python scrip.