![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2013\/07\/temp-thumb.jpg?resize=1200%2C896&quality=100&strip=all&ssl=1\")
<\/p>\nIn this project I’ll display the temperature in a 4 digit 7 segment display (common anode).<\/p>\n
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The sensor is the cheapest you can find so actually the temperature changes pretty easily which makes the display to show always different temperatures. But the idea is to apply this code to other projects with 7 segment displays that I might do later. You can also read more about 7 segment displays in this post.<\/a><\/p>\n This project is great to learn more about:<\/strong><\/p>\n You can use the preceding links or go directly to MakerAdvisor.com\/tools<\/a> to find all the parts for your projects at the best price!<\/p> This can also help you wiring because the Schematics I\u2019ve made using fritizing turned out a bit confusing. This is the 7 segment display internal circuit diagram<\/p>\n Basically \u00a0the pin 11 connects to the QA, the pin 7 to the QB and so one…<\/p>\n View raw code<\/a><\/p>\n![\"new\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2013\/04\/new.jpg?resize=324%2C242&quality=100&strip=all&ssl=1\")
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Parts required<\/h2>\n
![\"IMG_0287\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2013\/04\/IMG_02871.jpg?resize=331%2C248&quality=100&strip=all&ssl=1\")
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![](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2017\/10\/header-200.png?w=1200&quality=100&strip=all&ssl=1\")
<\/a><\/p>\nSchematics<\/h2>\n
![\"circuit](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2013\/04\/circuit-diagram1.png?resize=430%2C353&quality=100&strip=all&ssl=1\" "\\"\\"")
<\/a><\/p>\n![\"images\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2013\/04\/images.jpg?resize=154%2C160&quality=100&strip=all&ssl=1\")
<\/p>\n![\"7](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2013\/04\/7-segment-4-digit-common-anode.png?resize=399%2C156&quality=100&strip=all&ssl=1\")
<\/a><\/strong><\/p>\nUpload the code below<\/h2>\n
\/*\n * Temperature Sensor Displayed on 4 Digit 7 segment common anode\n * Created by Rui Santos, http:\/\/randomnerdtutorials.com\n*\/\n\nconst int digitPins[4] = {\n 4,5,6,7}; \/\/4 common anode pins of the display\nconst int clockPin = 11; \/\/74HC595 Pin 11 \nconst int latchPin = 12; \/\/74HC595 Pin 12\nconst int dataPin = 13; \/\/74HC595 Pin 14\nconst int tempPin = A0; \/\/temperature sensor pin\nconst byte digit[10] = \/\/seven segment digits in bits\n{\n B00111111, \/\/0\n B00000110, \/\/1\n B01011011, \/\/2\n B01001111, \/\/3\n B01100110, \/\/4\n B01101101, \/\/5\n B01111101, \/\/6\n B00000111, \/\/7\n B01111111, \/\/8\n B01101111 \/\/9\n};\nint digitBuffer[4] = {\n 0};\nint digitScan = 0, flag=0, soft_scaler = 0;\n;\nfloat tempK, tempC, tempF, temp;\n \nvoid setup(){ \n for(int i=0;i<4;i++)\n {\n pinMode(digitPins[i],OUTPUT);\n }\n pinMode(tempPin, INPUT);\n pinMode(latchPin, OUTPUT);\n pinMode(clockPin, OUTPUT);\n pinMode(dataPin, OUTPUT); \n pinMode(tempPin, INPUT);\n}\n \n\/\/writes the temperature on display\nvoid updateDisp(){\n for(byte j=0; j<4; j++) \n digitalWrite(digitPins[j], LOW);\n \n digitalWrite(latchPin, LOW); \n shiftOut(dataPin, clockPin, MSBFIRST, B11111111);\n digitalWrite(latchPin, HIGH);\n \n delayMicroseconds(100);\n digitalWrite(digitPins[digitScan], HIGH); \n \n digitalWrite(latchPin, LOW); \n if(digitScan==2)\n shiftOut(dataPin, clockPin, MSBFIRST, ~(digit[digitBuffer[digitScan]] | B10000000)); \/\/print the decimal point on the 3rd digit\n else\n shiftOut(dataPin, clockPin, MSBFIRST, ~digit[digitBuffer[digitScan]]);\n \n digitalWrite(latchPin, HIGH);\n digitScan++;\n if(digitScan>3) digitScan=0; \n}\n \nvoid loop(){ \n tempK = (((analogRead(tempPin)\/ 1023.0) * 5.0) * 100.0); \n \/\/Converts Kelvin to Celsius minus 2.5 degrees error\n tempC = tempK - 273.0; \n tempF = ((tempK - 2.5) * 9 \/ 5) - 459.67;\n \/\/Celsius temperature display\n tempC = int(tempC*100);\n digitBuffer[3] = int(tempC)\/1000;\n digitBuffer[2] = (int(tempC)%1000)\/100;\n digitBuffer[1] = (int(tempC)%100)\/10;\n digitBuffer[0] = (int(tempC)%100)%10;\n updateDisp();\n delay(2);\n \n \/*\n \/\/Fahrenheit temperature display\n tempF = int(tempF*100);\n digitBuffer[3] = int(tempF)\/1000;\n digitBuffer[2] = (int(tempF)%1000)\/100;\n digitBuffer[1] = (int(tempF)%100)\/10;\n digitBuffer[0] = (int(tempF)%100)%10;\n updateDisp();\n delay(2);\n *\/\n}\n<\/code><\/pre>\n\tWatch the video demonstration<\/h2>\n