| buffalobillpatrick |
02-18-15 04:45 PM |
Arduino Subcooling code
Subcooling only code:
Code:
/********************************************************
*
* ARDUINO R290 Calculate Subcooling
*
* Note: REQUIRED SENSOR
* High Pressure Sensor: 0-300PSI with output of .5 -> 4.5vdc
*
* If in DEBUG mode, values are forced to test code function
*
* In Void Loop:
*
* , read Hi Side Pressure Transducer
*
* , if RAW_ADC is in bounds:
* , convert Raw_ADC to PSI
* , calc_R290_Saturated_Temp
* , read Subcooling_Temp_sensor (analog NTC thermistor)
* , calc Subcooling
*
* , if RAW_ADC is out of bounds, Hang Forever
*
* Repeat Void loop
*
*
* Change History:
* 02/18/15 Coded, BBP
*
*
*
********************************************************/
#if defined(ARDUINO) && ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>
#define DEBUG 1
//#define DEBUG 0
#define I2C_ADDR 0x3F // <<----- Add your address here. Find it from I2C Scanner
//D3
#define BACKLIGHT_PIN 3 //define LCD digital pins
#define En_pin 2
#define Rw_pin 1 //can't use D0 & D1 Tx, Rx
#define Rs_pin 0
#define D4_pin 4
#define D5_pin 5 //can use D2 -> D12 below in code
#define D6_pin 6
#define D7_pin 7
LiquidCrystal_I2C lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);
#define SDA A4 //RESERVE I2C for LCD
#define SCL A5
// pinMode(A0, OUTPUT); //This works acording
// http://arduino.cc/en/Tutorial/AnalogInputPins
// digitalWrite(A0, HIGH); //
#define Subcooling_Temp_sensor_pin A0
#define Hi_Side_Pressure_Transducer_pin A1
#define ADC_Low_Limit 102.0 //ADC of .5v
#define ADC_Hi_Limit 921.0 //ADC of 4.5v
#define PSI_min 0.0
#define PSI_max 300.0
float Raw_ADC, Hi_Side_PSI, Subcooling_T, Subcooling, Saturated_Temp;
int Y;
void setup(void) //Start Setup
{
pinMode (Subcooling_Temp_sensor_pin, INPUT);
pinMode (Hi_Side_Pressure_Transducer_pin, INPUT);
// Serial.begin(9600); // start serial communication
// delay(10000); //time to enable monitor window
// Serial.println(F("........Hello world!......."));
// delay(100);
lcd.begin (16,2); // <<----- My LCD is 16x2
lcd.clear();
//Switch on the backlight
lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE);
lcd.setBacklight(HIGH);
lcd.clear();
lcd.home (); // go home
lcd.print(F("R290_SUBCOOL_3"));
delay(10000);
if(DEBUG)
{
lcd.clear();
lcd.home (); // go home
lcd.print(F("DEBUG = ON"));
delay(10000);
}
else
{
lcd.clear();
lcd.home (); // go home
lcd.print(F("DEBUG = OFF"));
delay(10000);
}
} //end setup
void loop ()
{
Raw_ADC = analogRead(Hi_Side_Pressure_Transducer_pin); //read Hi Side pressure
if(DEBUG){ Raw_ADC = 921;}
//Raw_ADC Bounds check
if ((Raw_ADC >= ADC_Low_Limit) && (Raw_ADC <= ADC_Hi_Limit))
{
// in bounds, convert Raw_ADC to PSI
Hi_Side_PSI = mapfloat(Raw_ADC, ADC_Low_Limit, ADC_Hi_Limit, PSI_min, PSI_max);
lcd.clear();
lcd.home (); // go home
lcd.print(F("SUBCOL_PSI="));
lcd.print(Hi_Side_PSI);
delay(10000);
Saturated_Temp = calc_R290_Saturated_Temp(Hi_Side_PSI);
lcd.clear();
lcd.home (); // go home
lcd.print(F("SAT_T="));
lcd.print(Saturated_Temp);
lcd.print(F("*F"));
delay(10000);
//read Subcooling Temp sensor
Subcooling_T = (Read_10K_NTC (Subcooling_Temp_sensor_pin));
if(DEBUG){ Subcooling_T = 150;}
lcd.clear();
lcd.home (); // go home
lcd.print(F("SUBCOL_T="));
lcd.print(Subcooling_T);
lcd.print(F("*F"));
delay(10000);
Subcooling = Subcooling_T - Saturated_Temp; //calc Subcooling
lcd.clear();
lcd.home (); // go home
lcd.print(F("SUBCOOL="));
lcd.print(Subcooling);
lcd.print(F("*F"));
delay(10000);
} //end if in bounds
else //ADC out of bounds
{
lcd.clear();
lcd.home (); // go home
lcd.print(F("RAW_PSI_NG"));
lcd.setCursor(0,1);
lcd.print(F("HANG_FOREVER_1"));
do{Y = Y;} while (Y == Y); //hang forever
}
} //end forever loop
float mapfloat(float x, float in_min, float in_max, float out_min, float out_max)
{
return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}
float calc_R290_Saturated_Temp(float psi)
{
//MMF Model: y=(a*b+c*x^d)/(b+x^d)
//Coefficient Data:
float a = -6.63511955666E+001;
float b = 6.30623048298E+001;
float c = 7.72874234743E+002;
float d = 5.32503085812E-001;
float p;
p = pow(psi,d);
return (((a * b) + (c * p)) / (b + p ));
}
int Read_10K_NTC (int which_sensor)
{
#define sample_cnt 30
float alpha = 0.9; // factor to tune
float average = 0.0;
float steinhart;
int I;
// resistance at 25 degrees C
#define THERMISTORNOMINAL 10000
// TEMP. for nominal resistance (almost always 25 C)
#define TEMPERATURENOMINAL 25
// The beta coefficient of the thermistor (usually 3000-4000)
#define BCOEFFICIENT 3892
// the value of the series resistor
#define SERIESRESISTOR 10000
for (I=0; I< sample_cnt; I++)
{
average = alpha * analogRead(which_sensor) + (1-alpha) * average;
delay(10);
}
// convert the value to resistance
average = 1023 / average - 1;
average = SERIESRESISTOR / average;
steinhart = average / THERMISTORNOMINAL; // (R/Ro)
steinhart = log(steinhart); // ln(R/Ro)
steinhart /= BCOEFFICIENT; // 1/B * ln(R/Ro)
steinhart += 1.0 / (TEMPERATURENOMINAL + 273.15); // + (1/To)
steinhart = 1.0 / steinhart; // Invert
steinhart -= 273.15; // convert to C
return (round(steinhart * 1.8) + 32); // round to whole number
// & convert to F
} // end of Read_10K_NTC
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