{"page":"\u003clink rel=\"stylesheet\" href=\"https://lessonplanet.com/assets/packs/css/resources-572d6a42.css\" /\u003e\n\u003clink rel=\"stylesheet\" href=\"https://lessonplanet.com/assets/packs/css/lp_boclips_stylesheets-f4d0de30.css\" media=\"all\" /\u003e\n\u003cdiv data-title='Tutorial 09: How to read voltages with analogRead(): Arduino Course for Absolute Beginners (ReM)' data-url='/boclips/videos/62a0e4888b9cc0130f1cb6ee' data-video-url='/boclips/videos/62a0e4888b9cc0130f1cb6ee' id='bo_player_modal'\u003e\n\u003cdiv class='boclips-resource-page modal-dialog panel-container'\u003e\n\u003cdiv class='react-notifications-root'\u003e\u003c/div\u003e\n\u003cdiv class='rp-header'\u003e\n\u003cdiv class='rp-type'\u003e\n\u003ci aria-hidden='true' class='fai fa-regular fa-circle-play'\u003e\u003c/i\u003e\nVideo\n\u003c/div\u003e\n\u003ch1 class='rp-title' id='video-title'\u003e\nTutorial 09: How to read voltages with analogRead(): Arduino Course for Absolute Beginners (ReM)\n\u003c/h1\u003e\n\u003cdiv class='rp-actions'\u003e\n\u003cdiv class='mr-1'\u003e\n\u003ca class=\"btn btn-success\" data-posthog-event=\"Signup: LP Signup Activity\" data-posthog-location=\"body_link_boclips\" data-remote=\"true\" href=\"/subscription/new\"\u003e\u003cspan\u003e\u003cspan\u003eGet Free Access\u003c/span\u003e\u003cspan class=\"\"\u003e for 10 Days\u003c/span\u003e\u003cspan\u003e!\u003c/span\u003e\u003c/span\u003e\u003c/a\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class='rp-body'\u003e\n\u003cdiv class='rp-info'\u003e\n\u003cdiv aria-label='Hide resource details' class='rp-hide-info' role='button' tabindex='0'\u003e\u0026times;\u003c/div\u003e\n\u003ci aria-label='Expand resource details' class='rp-expand-info fai fa-solid fa-up-right-and-down-left-from-center' role='button' tabindex='0'\u003e\u003c/i\u003e\n\u003ci aria-label='Compress resource details' class='rp-compress-info fai fa-solid fa-down-left-and-up-right-to-center' role='button' tabindex='0'\u003e\u003c/i\u003e\n\u003cdiv class='rp-rating'\u003e\n\u003cspan class='resource-pool'\u003e\n\u003cspan class='pool-label'\u003ePublisher:\u003c/span\u003e\n\u003cspan class='pool-name'\u003e\n\u003cspan class='text'\u003e\u003ca data-publisher-id=\"30358947\" href=\"/search?publisher_ids%5B%5D=30358947\"\u003eProgramming Electronics Academy\u003c/a\u003e\u003c/span\u003e\n\u003c/span\u003e\n\u003c/span\u003e\n\u003c/div\u003e\n\u003cdiv class='rp-description'\u003e\n\u003cspan class='short-description'\u003eIn the last lesson you learned about using the analogRead() function to collect data from a sensor connected to one of the Arduino' analog pins.  The range of data we received from the analogRead() function, was mapped from 0 to 1023. ...\u003c/span\u003e\n\u003cspan class='full-description hide'\u003eIn the last lesson you learned about using the analogRead() function to collect data from a sensor connected to one of the Arduino' analog pins.  The range of data we received from the analogRead() function, was mapped from 0 to 1023.  What if we wanted to know the actual voltage being applied at the pin?\u003cbr/\u003e\u003cbr/\u003eYou Will Need\u003cbr/\u003e\u003cbr/\u003ePotentiometer (any resistance range will work)\u003cbr/\u003eJumper Wires - at least 3\u003cbr/\u003esolder-less breadboard\u003cbr/\u003ePersian Rug\u003cbr/\u003eStep-by-Step Instructions\u003cbr/\u003e\u003cbr/\u003ePlace your potentiometer into your breadboard.\u003cbr/\u003eRun a jumper wire from the 5-Volt pin of the Arduino either one of the outside pins of your potentiometer.\u003cbr/\u003eRun another jumper wire from one of the ground pins on your Arduino (labeled GND) to the other outside pin of your potentiometer.\u003cbr/\u003eRun the final jumper wire from pin A0 on your Arduino to the middle pin of the potentiometer.\u003cbr/\u003ePlug your Arduino into your computer.\u003cbr/\u003eOpen up the Arduino IDE.\u003cbr/\u003eGo to File, Examples, 01.Basics, ReadAnalogVoltage\u003cbr/\u003eClick the Verify button on the top left side of the screen. It will turn orange and then back to blue once it has finished.\u003cbr/\u003eClick the Upload button (next to the Verify button). It will turn orange and then back to blue once it has finished.\u003cbr/\u003eOn the menu bar, go to Tools, Serial Monitor - this will open the Serial Monitor window - you should see numbers rolling down this screen.\u003cbr/\u003eNow adjust the knob of your potentiometer and watch the serial monitor window, the numbers should adjust between 0 and 5.\u003cbr/\u003e\u003cbr/\u003eThis sketch does the exact same thing the last lesson covered except for one important change.  It takes the reading provided by the analogRead() function and converts it into the actual voltage value at the respective analog pin.  Let's start from the top just to review what is taking place...\u003cbr/\u003e\u003cbr/\u003eWe have no variable to declare and initialize at the beginning of the sketch so we jump right into the setup() function.  Inside the curly braces of setup() we begin serial communications by setting the baud rate.  This is done using the function Serial.begin(9600).\u003cbr/\u003e\u003cbr/\u003eThat is all there is to the setup of this sketch.  the next block of code is loop().  Inside the curly braces of loop() the first thing we do is read the value at analog pin A0 and assign it to an integer variable called sensorValue.\u003cbr/\u003e\u003cbr/\u003eint sensorValue = analogRead(A0);\u003cbr/\u003e\u003cbr/\u003eOnce we have recorded this value,  we now want to convert it to an actual voltage.  You will recall that the range returned by the analogRead() function is between 0 and 1023.  We want this to reflect the actual voltage at the pin - which is between 0 and 5 volts depending on where we have our potentiometer turned to.  So lets take a look at how we might accomplish this...\u003cbr/\u003e\u003cbr/\u003efloat voltage = sensorValue * (5.0 / 1023.0);\u003cbr/\u003e\u003cbr/\u003eThe first thing we encounter is a new data type - called float.   A float is just a number with a decimal point; say for example 3.14 or 2.17781778.  Floats, also called floating point numbers, can be huge in value, and take much more time for the Arduino to churn through than integers - this is why they are avoided unless necessary.\u003cbr/\u003e\u003cbr/\u003eWe want a float in this case because it will give us more resolution than an integer.\u003cbr/\u003e\u003cbr/\u003eSo what is that calculation anyway - it looks kind of confusing.  The numbers on the right are just a conversion factor.  We want to convert one scale to another.\u003cbr/\u003e\u003cbr/\u003eWhen we multiply this small number times the sensorValue variable, it will scale down the range from 0-1023 (which is the range that analogRead() returns) to the range 0-5 which is the actual range of the voltage.\u003cbr/\u003e\u003c/span\u003e\n\u003c/div\u003e\n\u003cdiv class='action-container flex justify-between'\u003e\n\u003cbutton aria-expanded='false' aria-label='Read more description' class='rp-full-description' type='button'\u003e\n\u003ci class='fai fa-solid fa-align-left'\u003e\u003c/i\u003e\n\u003cspan id='read_more'\u003eRead More\u003c/span\u003e\n\u003c/button\u003e\n\u003cdiv class='rp-report'\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv aria-labelledby='resource-details-heading' class='rp-info-section'\u003e\n\u003ch2 class='title' id='resource-details-heading'\u003eResource Details\u003c/h2\u003e\n\u003cdiv class='rp-resource-details clearfix'\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eCurator Rating\u003c/dt\u003e\n\u003cdd\u003e\u003cspan class=\"star-rating\" aria-label=\"4.0 out of 5 stars\" role=\"img\"\u003e\u003ci class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"\u003e\u003c/i\u003e\u003ci class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"\u003e\u003c/i\u003e\u003ci class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"\u003e\u003c/i\u003e\u003ci class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"\u003e\u003c/i\u003e\u003ci class=\"fa-regular fa-star text-action\" aria-hidden=\"true\"\u003e\u003c/i\u003e\u003c/span\u003e\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt class=\"educator-rating-title\"\u003eEducator Rating\u003c/dt\u003e\u003cdd\u003e\u003cdiv class=\"educator-rating-details\" data-path=\"/educator_ratings/rrp_data?resourceable_id=199452\u0026amp;resourceable_type=Boclips%3A%3AVideoMetadata\"\u003e\u003cspan class=\"not-yet-rated\"\u003eNot yet Rated\u003c/span\u003e\u003c/div\u003e\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eMedia Length\u003c/dt\u003e\n\u003cdd\u003e14:00\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eGrade\u003c/dt\u003e\u003cdd title=\"Grade\"\u003eHigher Ed\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eSubjects\u003c/dt\u003e\u003cdd\u003e\u003cspan\u003e\u003ca href=\"/search?grade_ids%5B%5D=259\u0026amp;search_tab_id=1\u0026amp;subject_ids%5B%5D=378077\"\u003eSTEM\u003c/a\u003e\u003c/span\u003e\u003c/dd\u003e\u003cdd class=\"text-muted\"\u003e\u003ci class=\"fa-solid fa-lock mr5\"\u003e\u003c/i\u003e3 more...\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eMedia Type\u003c/dt\u003e\u003cdd\u003e\u003cspan\u003e\u003ca href=\"/search?grade_ids%5B%5D=259\u0026amp;search_tab_id=2\u0026amp;type_ids%5B%5D=4543647\"\u003eInstructional Videos\u003c/a\u003e\u003c/span\u003e\u003c/dd\u003e\n\u003c/dl\u003e\n\u003c/div\u003e\n\u003cdiv class='detail'\u003e\n\u003cdl\u003e\n\u003cdt\u003eSource:\u003c/dt\u003e\n\u003cdiv class='preview-source' data-animation='true' data-boundary='.rp-info' data-container='.rp-resource-details' data-html='false' data-title='Got questions about Arduino? 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