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‫Welcome to the temperature sensor interface demonstration.

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‫But the base is three board whose demonstration we're using two four did seven segment displays with

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‫all the segments tied together through a 56 ohm resistor and all these are then fed into the j j b p

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‫mod port.

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‫We also have all the digits flex our control with two in thirty nine or four and transistors with the

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‫470 ohm resistor connected to the base.

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‫And these are fed into the J.

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‫C. P. core of the basic three development board.

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‫We also have the external temperature sensor now with the basic 3 board.

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‫It does not support a single ended analog signal.

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‫So you have to feed both the negative and the positive.

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‫And also with the X ADC core on the actual Arctic's FPGA chip you can't feed it a 3.3 volt signal.

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‫It can only handle a signal from 0 to 1 volt.

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‫So what we do is we are dividing down the circuit the analog signal is reading takes in a three point

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‫three volt signal.

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‫So we have to reference our voltage to that 3.3 volt reference.

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‫And so we have a voltage divider circuit which you can see is just consisted of three 2.2 ohm resistors.

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‫Now these are 5 percent resistors not your 1 percent or point 1 percent tolerance resistors if you wanted

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‫to have a super accurate temperature sensor.

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‫You want to have a lot more accurate resistors but this just shows you the point that you can read a

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‫temperature value off of this.

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‫And as you can see we also have a slide switch 15 which is used to reset or are unable or our temperature

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‫reading.

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‫So if I pull that high it goes into a reset state where everything's at zero.

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‫And our two other segments the one that indicates were negative or positive goes to an A and the one

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‫that tells us if we're Celsius or Fahrenheit goes to an 8 because the micro blaze core we're using has

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‫a default setting of setting everything to zero when it's in a reset.

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‫So we pulled out of reset and now we can see we have a temperature of seventy nine point six five degrees

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‫Fahrenheit.

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‫So I can make that go higher by holding the temperature sensor.

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‫If I put my fingers on there and hold it you'll see it jumps up there.

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‫We just went up to 84 and you'll notice it doesn't jump up right away.

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‫That's because we have a little delay built into the microbus processor where every half second we take

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‫a reading and then update the measurement.

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‫And that's just because your temperature typically doesn't jump around a whole lot.

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‫It doesn't change super fast so a half second is more than fast enough for an update rate.

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‫We also have our switch to zero which toggles between Fahrenheit and Celsius.

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‫And currently we're in Fahrenheit which you can see by the denoted by the F we have on the end of our

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‫display.

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‫And if we pull that low the next time we update you'll see we're now twenty seven point eight four degrees

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‫Celsius.

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‫And if I toggle back up we'll go back to Fahrenheit.

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‫So you can switch back and forth.

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‫And this is just an example of the temperature sensor interface demonstration running on the basis three

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‫development board.