Create new object of a class

Projects Programming
1

Hi, I wrote a Class for my Honeywell HSS Pressure transducer.

Everything works fine when I read only one. If I want to use this class with a second Sensor, all my values are rubbish. Is there a problem with my SPI Port? Am I not terminating it correctly?

#include "HSS.h"
#include "SPI.h"


HSS absolutePress = HSS(2);
//HSS relativePress = HSS(3);
void setup() {
  Serial.begin(9600);
  

}
void loop()
{
  delay(1000);
  float val1 =  (1600 * ((float)absolutePress.getPressure() - 1638) / 13107);
  Serial.print("PRESS1 = "); Serial.println(val1);
  Serial.print("Temp1 = "); Serial.println(absolutePress.getTemperature());
  //float val2 =  (40 * ((float)relativePress.getPressure() - 1638) / 4369) - 60;
  //Serial.print("PRESS2 = "); Serial.println(val2);
  //Serial.print("Temp2 = "); Serial.println(relativePress.getTemperature());
  
}

#include "HSS.h"
#include "Arduino.h"
#include "SPI.h"
//Define Communication Settings
#define baudrate 500000
#define BitFirst MSBFIRST
#define SPIMode SPI_MODE3
#define DEBUG 0

uint8_t ChipselectPin = 0;
float temperature = 0;
int16_t pressure = 0;
HSS::HSS(uint8_t ChipSelect) {
  ChipselectPin = ChipSelect;
  pinMode(ChipselectPin, OUTPUT);
  digitalWrite(ChipselectPin, HIGH);
}


float HSS::getTemperature() {
  readSensor();
  return temperature;
}

uint16_t HSS::getPressure() {
  readSensor();
  return pressure;
}

void HSS::readSensor() {
  SPI.begin();
  digitalWrite(ChipselectPin, LOW);       //pull Chipselect Pin to Low
  SPI.beginTransaction(SPISettings(baudrate, BitFirst, SPIMode)); // Set to 800kHz, MSB and MODE1


  int inByte_1 = SPI.transfer(0x00);  // Read first Byte of Pressure
  int inByte_2 = SPI.transfer(0x00);  // Read second Byte of Pressure
  int inByte_3 = SPI.transfer(0x00);  // Read first Byte of Temperature
  int inByte_4 = SPI.transfer(0x00);  // Read second Byte of Temperature

  if (DEBUG) {
    Serial.print("Chipselect = "); Serial.print(ChipselectPin, DEC); Serial.print(" ");
    Serial.print("Byte_1 = "); Serial.print(inByte_1, DEC); Serial.print(" ");
    Serial.print("Byte_2 = "); Serial.print(inByte_2, DEC); Serial.print(" ");
    Serial.print("Byte_3 = "); Serial.print(inByte_3, DEC); Serial.print(" ");
    Serial.print("Byte_4 = "); Serial.print(inByte_4, DEC); Serial.print(" ");
  }

  SPI.endTransaction();               //end SPI Transaction
  SPI.end();
  digitalWrite(ChipselectPin, HIGH);      //pull Chipselect Pin to High
  pressure = inByte_1 << 8 | inByte_2;

  inByte_3 = inByte_3 << 3 | inByte_4; //Shift first Temperature byte 3 left
  temperature = ((float)inByte_3 * 200 / 2047) - 50; //Convert Digital value to °C
  if (DEBUG) {
    Serial.print("Temp[C]= "); Serial.print(temperature); Serial.print(" ");
  }
}

#include "Arduino.h"
class HSS
{

  public:
    HSS(uint8_t ChipSelect);
    float getTemperature();
    uint16_t getPressure();
    void readSensor();
    

};

Also, how can I implement the SPI library without importing it to the main sketch? Is this possible?

Thanks!

3

You do realize that these variables:

uint8_t ChipselectPin = 0;
float temperature = 0;
int16_t pressure = 0;

are NOT members of your HSS class?

Regards,
Ray L.

4

RayLivingston:
You do realize that these variables:

uint8_t ChipselectPin = 0;

float temperature = 0;
int16_t pressure = 0;




are NOT members of your HSS class?

Regards,
Ray L.

And why? Or better, how do I add this variables as a member of my class?

5

how do I add this variables as a member of my class?

class HSS
{

  public:
    HSS(uint8_t ChipSelect);
    float getTemperature();
    uint16_t getPressure();
    void readSensor();
    

// class members go here, as either public: or private:
};