 Hey guys, it's Parker Domen, the Longhorn Engineer. I'm taking this class called EE-445L, which is microcontroller applications. Basically every week we have to design and develop and prototype a different solution using a microcontroller. We're using the Texas Instruments LM3S1968 evaluation board, which is an ARM. It's got nice OLED display, speaker buttons, and USB JTAG debugger. This is lab 7 that we did. It's basically a thermometer, a digital thermometer. Basically it's a thermal resistor, which is that guy right there, so you can see that guy. And so I'll walk you through what all this circuitry does. This is the amplifier. This amplifies this circuit over here. This is the resistor bridge area. Well thermal resistors are not linear in terms of their resistance in the temperature. And so this bridge is also non-linear. And so when you have two nonlinear systems, if you design them correctly, you can get a linear system out of it. And so that's what this attempts to do. So this is the amplifier chip. And then this is the low pass filter. Because we're sampling the ADC, we're sampling at 100 hertz, the ADC on the ARM chip. So this has a cutoff of 10 hertz. This is why we don't get any aliasing or anything like that, so you don't get any crazy fluctuations in your readings. This is just a shunt diode. This gets the reference voltage for the amplifier, pretty standard stuff. So if you look at the display, it's all off at about 28 degrees Celsius, which is about normal. And also we have the display also displays the resistance of the thermal resistor, roughly. It's probably within about 200 ohms, which is close enough. So if I hold the thermal resistor with my fingers, the temperature should go up, and the harder I squeeze it, the more it goes up, because I'm putting more heat into the thermal resistor for my fingers. Now I'm not going to be able to get to body temperature, because your fingers are a little bit cooler than your core body temperature, but 31.9, 31.8, pretty good. So if we release it, drops back down to room temperature.