1 00:00:05,030 --> 00:00:10,280 ‫Welcome to the temperature sensor interface demonstration with the Arties the seven development board 2 00:00:10,850 --> 00:00:17,990 ‫we have two external four digit 7:7 displays on the breadboard where they're all tied together through 3 00:00:18,000 --> 00:00:23,390 ‫a 56 ohm resistors that are fed into the JHP mod port. 4 00:00:23,390 --> 00:00:28,270 ‫Each of the digits on the seven second display are controlled through an end to end. 5 00:00:28,280 --> 00:00:34,660 ‫Thirty nine of four transistor with a 470 ohm resistor connected to the base. 6 00:00:34,670 --> 00:00:38,570 ‫These are all controlled by the J b p mod port. 7 00:00:38,570 --> 00:00:45,710 ‫We also have the external aid external voltage temperature regulator which is connected on a separate 8 00:00:45,710 --> 00:00:52,950 ‫breadboard that goes into the zero analog input which is the chip kit or Adreno header on the Arties 9 00:00:53,030 --> 00:00:58,600 ‫7 development board and we're pulling power from the original. 10 00:00:58,750 --> 00:01:07,130 ‫Our breadboard and the way the circuit works is we have this external temperature regulator that takes 11 00:01:07,130 --> 00:01:11,710 ‫a temperature and gives a voltage output that is in relation to the temperature. 12 00:01:11,750 --> 00:01:17,750 ‫We take the analog voltage reading convert it and do some calculations on it and we will determine what 13 00:01:17,750 --> 00:01:18,980 ‫the temperature is. 14 00:01:19,220 --> 00:01:23,130 ‫And right now we have we're displaying in Fahrenheit. 15 00:01:23,150 --> 00:01:31,580 ‫If I switch my switch 0 to low it will then go ahead and display the temperature in Celsius. 16 00:01:31,580 --> 00:01:38,360 ‫Now you'll notice that it takes about anywhere from right away to about a half a second until the conversion 17 00:01:38,360 --> 00:01:39,260 ‫takes place. 18 00:01:39,260 --> 00:01:44,750 ‫And that's because in the software we have a delay which is approximately a half a second delay where 19 00:01:44,750 --> 00:01:50,370 ‫we wait until we actually take another 80 reading and give a temperature output. 20 00:01:50,370 --> 00:01:54,710 ‫And so if I toggle my switch one high or low right now it's low. 21 00:01:54,710 --> 00:02:01,310 ‫So we're active but if I switch it high all my digits will go to zero and my two digits will go to eight. 22 00:02:01,430 --> 00:02:06,350 ‫That's because the microblog is soft core process or we're using by default. 23 00:02:06,500 --> 00:02:12,860 ‫When you're when you're not using or controlling it or in a reset state whose output ports are defaulted 24 00:02:12,860 --> 00:02:13,540 ‫to zero. 25 00:02:13,610 --> 00:02:19,190 ‫And so that's why there's eight express there all the segments are lit up and so to show that this is 26 00:02:19,190 --> 00:02:23,290 ‫working crack it will enable it and I'll switch it back to Fahrenheit. 27 00:02:23,960 --> 00:02:29,110 ‫And if you look at the temperature you'll notice it says sixty point seventy nine degrees Fahrenheit. 28 00:02:29,150 --> 00:02:34,400 ‫If I put my finger and hold it on here you'll see it went up right there sixty two point two five. 29 00:02:34,530 --> 00:02:40,100 ‫And the next reading after that should go up even higher 71 and I can hold on to it and I'll keep going 30 00:02:40,100 --> 00:02:44,350 ‫up until it reaches approximately the temperature of my hand. 31 00:02:44,360 --> 00:02:47,590 ‫Now if I let go and see it may it will start to slow. 32 00:02:47,590 --> 00:02:53,050 ‫They drop their 72 and keep going down until it reaches approximate the room temperature again around 33 00:02:53,050 --> 00:02:54,650 ‫the 60 degrees. 34 00:02:54,650 --> 00:02:56,930 ‫And so you can test this when you actually have the circuit. 35 00:02:56,930 --> 00:03:02,060 ‫I would suggest you take it and look at the thermometer or thermostat in your room or the room with 36 00:03:02,060 --> 00:03:07,610 ‫chair running in and just to give it a comparison the thermostat in my room says it's approximately 37 00:03:07,880 --> 00:03:10,050 ‫61 or 62 degrees. 38 00:03:10,250 --> 00:03:18,040 ‫And if you look at the days of this component that it says it it's accurate up to approximately 2 degrees. 39 00:03:18,080 --> 00:03:23,630 ‫So and that's exactly what it is right here is kind of hovering around a two to remark of what my thermostat 40 00:03:23,810 --> 00:03:27,830 ‫on the House is saying and there are other things you could do if you wanted to really get this even 41 00:03:27,830 --> 00:03:29,670 ‫more accurate you could calibrate it. 42 00:03:29,840 --> 00:03:36,000 ‫Measure what the actual reading of the 3.3 volt references and use that as opposed to 3.3. 43 00:03:36,170 --> 00:03:41,310 ‫But we just use a 3.3 that way we can use it throughout different development boards. 44 00:03:41,390 --> 00:03:42,810 ‫So on and so forth. 45 00:03:43,010 --> 00:03:48,440 ‫And that is a demonstration of the temperature sensor interface running on the arm of the seven development 46 00:03:48,440 --> 00:03:48,900 ‫board.