‫Welcome to the temperature sensor lab set up lecture for the temperature sensor labs there are several
‫devices we'll be using will need to be using eight different digits of a seven segment display.
‫So we have two of the four digit seven semi displays where we're tying all the segments of these displays
‫together through a 56 ohm resistor that is then connected to the actual FPGA so they can control each
‫of the individual segments which Winds light up and which ones do not.
‫And then also each of the digits selects are connected through an individual two and thirty nine or
‫four endpin transistor but the 470 ohm resistor connected to the base.
‫And these are all fed out and controlled to the FPGA as well.
‫So they're controlling the digits and they're controlling the individual LCD segments so we do sort
‫of a multiplexing operation where we light up each of the segments so fast that one can't tell half
‫how fast their appears are all lit up simultaneously and for the digits the first digit we're using
‫to indicate whether or not the temperature is negative or positive is positive or just leave it alone
‫and won't light it up if it's negative.
‫What does light up the middle segment indicate a negative sign.
‫And then the next five digits we're using to represent the temperature where the first three are before
‫the decimal and the second two are after the decimal.
‫So the highest temperature we could theoretically display is nine hundred ninety nine point nine nine
‫degrees.
‫Now whether you're Fahrenheit or Celsius that's really hot and the sensor will break or melt down before
‫reaching that point so we don't have to worry about that.
‫And in the last two digits the next digit we're using to represents the degree sign.
‫So we're just light up the four top segments and the last digit we used to represent whether were displayed
‫and Fahrenheit or celcius.
‫So either display an F or a C.
‫And so that's how the 7 segment display will be set up and that's what we're going to be using to actually
‫display our our temperature the measurement that we're reading.
‫Now we also have the temperature sensor which is a three pin device and it's got one of the pins is
‫tied to ground.
‫The other is tied to Vcc or in this case 3.3 volts for all the APJ Develin boards we're using and the
‫other is the output.
‫The output is a voltage that changes nearly linearly with temperature.
‫So you take that that voltage reading and you convert that to an actual temperature.
‫And then based on that value you can then display it on the Seven same display.
‫And so in order to actually do the math operations we're going to be using soft core processors.
‫So we'll be using the microblog software processors for the Xilinx and we'll be using the NIOS soft
‫core processors for the terrible hours and that is the lab set up for the temperature sensor interface.