#madewithcode

To that ONE teacher who always supports you,

To that ONE teacher for whom you are family,

To that ONE teacher who is always on your side,

To that ONE teacher who always eases your test anxiety with motivating words,

To that ONE teacher who believes in you more than you believe in yourself,

To that ONE teacher who wants to see you doing well in life,

To that ONE teacher,

I HOPE I MAKE YOU HAPPY THIS EXAM SEASON.

THANK YOU for your love and support -  my THAT ONE TEACHER.

I’m building an ultra high vacuum system, and have been accruing parts over time. I just recently wrote my first arduino program, a program that takes the voltage from the gauge, and converts it to a pressure reading in torr via a logarithmic scale equation.

The code is quite simple, thanks to the help of PaulRB and the fantastic arduino community forums!

#include <LiquidCrystal.h> #include <math.h> // initialize the library with the numbers of the interface pins LiquidCrystal lcd(12, 11, 5, 4, 3, 2); // the setup routine runs once when you press reset:    void setup() {      // initialize serial communication at 9600 bits per second:      Serial.begin(9600);      pinMode(A0, INPUT);              //A0 is set as input      #define PRESSURE_SENSOR A0;            lcd.begin(16, 2);      lcd.print("MKS  Instruments");      lcd.setCursor(0, 1);      lcd.print("IMT Cold Cathode");      delay(6500);      lcd.clear();      lcd.print("Gauge Pressure:");          } // the loop routine runs over and over again forever:      void loop() {      float v = analogRead(A0);        //v is input voltage set as floating point unit on analogRead      v = v * 10.0 / 1024;             //v is 0-5v divider voltage measured from 0 to 1024 calculated to 0v to 10v scale      float p = pow(10, v - 11.000);   //p is pressure in torr, which is represented by k in the equation [P=10^(v-k)] which is-                                       // -11.000 (K  = 11.000 for Torr, 10.875 for mbar, 8.000 for microns, 8.875 for Pascal)       Serial.print(v);       char pressureE[8];       dtostre(p, pressureE, 1, 0);        // scientific format with 1 decimal places             lcd.setCursor(0, 1);       lcd.print(pressureE);       lcd.print(" Torr");    }

The code simply sets A0 as a floating point unit for voltage, which is 0-5v from the voltage divider. Then it is calculated back up to a 10v scale and interpolated using an equation based on the voltage/pressure table provided by the manufacturer.

The equation is P=10^(v-k) where p is pressure, v is voltage on a 10v scale and k is the unit, in this case torr, represented by 11.000. It calculates that in floating point, then displays it on an LCD screen in scientific notation using dtostre.