//Libraries#include <Arduino.h>#include <Wire.h>//constants & variablesbool error=0; //reading error variable (not used in this sketch)float pressureKPA=0.0; //declare pressure KPa variablefloat pressureCMH2O=0.0; //declare pressure cmH2O variablefloat temperatureC=0.0; //declare temperature Celsius variablefloat temperatureF=0.0; //declare temperature Fahrenheitlong startMillis=0; //start sampling milliseconds timeconst long period=2000; //time between samples in milliseconds//hardware settings//functionsbool readCFSensor(float &temp, float &press,byte sensorAddress);void setup() { Serial.begin(9600); //begin serial port Wire.begin(); //begin i2c bus delay(200); //wait for electronics}void loop() { Serial.println(""); // Serial.println(F("-------------------------------------------------------------------------")); //samples division Serial.println(""); // startMillis=millis(); //save the starting time error = readCFSensor(temperatureC,pressureKPA,0x6D); //start conversion and read on pressure sensor ad 0x6D address Serial.println("Temperature *C: " + String(temperatureC,1)); //print *C temperature temperatureF= temperatureC * 1.8 + 32; //*C to *F conversion Serial.println("Temperature *F: " + String(temperatureF,1)); //print *F temperature Serial.println("Pressure KPa: " + String(pressureKPA,3)); //print KPa pressure pressureCMH2O = pressureKPA * 10.1972; //KPa to cmH2O conversion Serial.println("Pressure cmH2O: " + String(pressureCMH2O,2)); //print cmH2O pressure while((millis()-startMillis) < period); //waits until period done}bool readCFSensor(float &temp, float &press,byte sensorAddress) { byte reg0xA5=0; Wire.beginTransmission(sensorAddress); //send Start and sensor address Wire.write(0xA5); //send 0xA5 register address Wire.endTransmission(); //send Stop Wire.requestFrom(sensorAddress,byte(1)); //send Start and read 1 byte command from sensor address if(Wire.available()){ //check if data is available on i2c buffer reg0xA5 = Wire.read(); //read 0xA5 register value } Wire.endTransmission(); //send Stop Serial.println("Register 0xA5 read: " + String(reg0xA5,HEX)); //for debugging purposes reg0xA5 = reg0xA5 & 0xFD; //mask 0xA5 register AND 0xFD to set ADC output calibrated data Wire.beginTransmission(sensorAddress); //send Start and sensor address Wire.write(0xA5); //send 0xA5 register address Wire.write(reg0xA5); //send 0xA5 regiter new value Wire.endTransmission(); //send Stop Serial.println("Write 0xA5 register: " + String(reg0xA5,HEX)); //for debugging purposes Wire.beginTransmission(sensorAddress); //send Start and sensor address Wire.write(0x30); //send 0x30 register address Wire.write(0x0A); //set and start combined conversion Wire.endTransmission(); //send Stop Serial.println("Write 0x0A on 0x30 register and start conversion"); //for debugging purposes byte reg0x30 = 0x08; //declare byte variable for 0x30 register copy (0x08 initializing for while enter) while((reg0x30 & 0x08) > 0) { //loop while bit 3 of 0x30 register copy is 1 delay(1); //1mS delay Wire.beginTransmission(sensorAddress); //send Start and sensor address Wire.write(0x30); //send 0x30 register address Wire.endTransmission(); //send Stop Wire.requestFrom(sensorAddress,byte(1));//send Start and read 1 byte command from sensor address if(Wire.available()){ //check if data is available on i2c buffer reg0x30 = Wire.read(); //read 0x30 register value } Wire.endTransmission(); //send Stop Serial.println("Register 0x30 read: " + String(reg0x30,HEX)); //for debugging purposes } unsigned long pressure24bit; //declare 32bit variable for pressure ADC 24bit value byte pressHigh=0; //declare byte temporal pressure high byte variable byte pressMid=0; //declare byte temporal pressure middle byte variable byte pressLow=0; //declare byte temporal pressure low byte variable Wire.beginTransmission(sensorAddress); //send Start and sensor address Wire.write(0x06); //send pressure high byte register address Wire.endTransmission(); //send Stop Wire.requestFrom(sensorAddress,byte(3)); //send Start and read 1 byte command from sensor address while(Wire.available() < 3); //wait for 3 byte on buffer pressHigh = Wire.read(); //read pressure high byte pressMid = Wire.read(); //read pressure middle byte pressLow = Wire.read(); //read pressure low byte Wire.endTransmission(); //send Stop Serial.print(String(pressHigh)); //for debugging purposes Serial.print("," + String(pressMid)); //for debugging purposes Serial.print("," + String(pressLow)); //for debugging purposes pressure24bit = pressure24bit | pressHigh; pressure24bit = pressure24bit & 0x000000FF; pressure24bit = pressure24bit << 8; pressure24bit = pressure24bit | pressMid; pressure24bit = pressure24bit & 0x0000FFFF; pressure24bit = pressure24bit << 8; pressure24bit = pressure24bit | pressLow; pressure24bit = pressure24bit & 0x00FFFFFF; Serial.print(":" + String(pressure24bit)); //for debugging purposes int temp16bit=0; //declare 16bit variable for temperature ADC value byte tempHigh=0; //declare temperature high byte variable byte tempLow=0; //declare temperature low byte variable Wire.beginTransmission(sensorAddress); //send Start and sensor address Wire.write(0x09); //send temperature high byte register address Wire.endTransmission(); //send Stop Wire.requestFrom(sensorAddress,byte(2)); //send Start and read 1 byte command from sensor address while(Wire.available() < 2); //wait for 2 byte on buffer tempHigh = Wire.read(); //read temperature high byte tempLow = Wire.read(); //read temperature low byte Wire.endTransmission(); //send Stop Serial.print(" - " + String(tempHigh)); //for debugging purposes Serial.print("," + String(tempLow)); //for debugging purposes temp16bit = tempHigh * 256 + tempLow; //merge of 16bit temperature ADC value Serial.println(":" + String(temp16bit)); //for debugging purposes temp = float(temp16bit)/256; //real Celsius temperature calculation if(pressure24bit > 8388608) { //check sign bit for twos complement press = (float(pressure24bit) - float(16777216)) * 0.0000078125; //KPa negative pressure calculation } else { //no sign press = float(pressure24bit) * 0.0000078125; //KPa positive pressure calculation } return 0;}Thanks Marcelo J. Pino from Telecomunicaciones

#include <reg52.h>#include <math.h>#define DELAY_TIME 600#define TRUE 1#define FALSE 0#define uchar unsigned char#define uint unsigned int //--------------define IIC SCL,SDA port------------------------------ sbit SCL = P1 ^ 7; sbit SDA = P1 ^ 6; //-----------------define Max7219 port---------------------------sbit Max7219_pinCLK = P2 ^ 2; sbit Max7219_pinCS = P2 ^ 1;sbit Max7219_pinDIN = P2 ^ 0;//-------------delay time_us-------------------------------void DELAY(uint t) { while (t != 0) t--;}//-------------IIC START CONDITION-------------------------------void I2C_Start(void) { SDA = 1; //SDA output high DELAY(DELAY_TIME); SCL = 1; DELAY(DELAY_TIME); //SCL output high SDA = 0; DELAY(DELAY_TIME); SCL = 0; DELAY(DELAY_TIME);} //-------------IIC STOP CONDITION-------------------------------void I2C_Stop(void) { SDA = 0; //SDA OUTPUT LOW DELAY(DELAY_TIME); SCL = 1; DELAY(DELAY_TIME); SDA = 1; DELAY(DELAY_TIME); SCL = 0; //SCL OUTPUT LOW DELAY(DELAY_TIME);}//-------------IIC SEND DATA "0"-------------------------------void SEND_0(void) { SDA = 0; DELAY(DELAY_TIME); SCL = 1; DELAY(DELAY_TIME); SCL = 0; DELAY(DELAY_TIME);}//-------------IIC SEND DATA "1"-------------------------------void SEND_1(void) { SDA = 1; DELAY(DELAY_TIME); SCL = 1; DELAY(DELAY_TIME); SCL = 0; DELAY(DELAY_TIME);}//-------------Check SLAVEs Acknowledge -------------------------------bit Check_Acknowledge(void) { SDA = 1; DELAY(DELAY_TIME); SCL = 1; DELAY(DELAY_TIME / 2); F0 = SDA; DELAY(DELAY_TIME / 2); SCL = 0; DELAY(DELAY_TIME); if (F0 == 1) return FALSE; return TRUE;}//-------------Write One Byte of Data -------------------------------void WriteI2CByte(uchar b) reentrant { char i; for (i = 0; i < 8; i++) if ((b << i) & 0x80) SEND_1(); else SEND_0();}//-------------Read One Byte of Data -------------------------------uchar ReadI2CByte(void) reentrant { char b = 0, i; for (i = 0; i < 8; i++) { SDA = 1; DELAY(DELAY_TIME); SCL = 1; DELAY(DELAY_TIME); //DELAY(10); F0 = SDA; DELAY(DELAY_TIME); //DELAY(10); SCL = 0; if (F0 == 1) { b = b << 1; b = b | 0x01; } else b = b << 1; } return b;}//-------------write One Byte of Data,Data from MASTER to the SLAVER -------------------------------//-------------SLAVER address bit:01101101-------------------------------void Write_One_Byte(uchar addr, uchar thedata) //Write "thedata" to the SLAVERs address of "addr"{ bit acktemp = 1; I2C_Start(); //IIC START WriteI2CByte(0xDA); //IIC WRITE operation,SLAVER address bit:01101010 acktemp = Check_Acknowledge(); //check the SLAVER WriteI2CByte(addr); /*address*/ acktemp = Check_Acknowledge(); WriteI2CByte(thedata); /*thedata*/ acktemp = Check_Acknowledge(); I2C_Stop(); //IIC STOP }//-------------Reaed One Byte of Data,Data from SLAVER to the MASTER -------------------------------uchar Read_One_Byte(uchar addr) { bit acktemp = 1; uchar mydata; I2C_Start(); WriteI2CByte(0xDA); acktemp = Check_Acknowledge(); WriteI2CByte(addr); acktemp = Check_Acknowledge(); I2C_Start(); WriteI2CByte(0xDB); //IIC READ operation acktemp = Check_Acknowledge(); mydata = ReadI2CByte(); acktemp = Check_Acknowledge(); I2C_Stop(); return mydata;}//-------------Delay_ms -------------------------------void Delay_xms(uint x) { uint i, j; for (i = 0; i < x; i++) for (j = 0; j < 112; j++) ;}//-------------Write One Byte to the Max7219-------------void Write_Max7219_byte(uchar DATA) { uchar i; Max7219_pinCS = 0; //CS low effect for (i = 8; i >= 1; i--) { Max7219_pinCLK = 0; Max7219_pinDIN = DATA & 0x80; DATA = DATA << 1; Max7219_pinCLK = 1; //when pinCLK is high send the Data }}//-------------decide which address shows the Data-------------void Write_Max7219(uchar address,uchar dat) { Max7219_pinCS = 0; Write_Max7219_byte(address); Write_Max7219_byte(dat); Max7219_pinCS = 1;}//-------------MAX_7219 Initialization-------------void Init_MAX7219(void) { Write_Max7219(0x09, 0xff); //Decoded mode：BCD code Write_Max7219(0x0a, 0x03); //Brightness Write_Max7219(0x0b, 0x07); //Scan limit：8 digital display Write_Max7219(0x0c, 0x01); //Power-Down modes ：0，Normal code：1 Write_Max7219(0x0f, 0x01); //Display test：1；Test end，normal display：0}void main(void){ uchar yali1, yali2, yali3,wendu1,wendu2; uchar temp_a5; long int ad,temp; long float pas; uchar dis[8]; Init_MAX7219(); Delay_xms(1000); Write_Max7219(0x0f, 0x00); while (1) { temp_a5 = Read_One_Byte(0xA5);//Read ASIC Sys_config temp_a5 = temp_a5 & 0xFD; //（Raw_data_on: 0: output calibrated data，namly the value in 0x06-0x0a） Write_One_Byte(0xA5, temp_a5); //Set ADC output calibrated Data Write_One_Byte(0x30, 0x0A); //indicate a combined conversion (once temperature conversion immediately followed by once sensor signal conversion)（wire measure order in 0x30，000：single temp. measure；001：single pressure. measure；010：combination：single pressure and temp. measurement；011：sleep mode（combined mode measurement at certain time intervals）） while ((Read_One_Byte(0x30) & 0x08) > 0); //Judge whether Data collection is over // -------------READ ADC output Data of Pressure ------------- yali1 = Read_One_Byte(0x06); yali2 = Read_One_Byte(0x07); yali3 = Read_One_Byte(0x08); ad = yali1 * 65536 + yali2 * 256 + yali3; // -------------READ ADC output Data of Temperature ------------- wendu1= Read_One_Byte(0x09); wendu2= Read_One_Byte(0x0a); temp=wendu1*256+wendu2; /*Conversion, the following is the conversion formula of 100*/ if (ad > 8388608) // >8388606 as negative value, handle at display end { pas = (ad - 16777216)/64/1000; //unit is kpa } else { pas = ad/64/1000; //unit is kpa } if (pas < 0) pas = fabs(pas);/*Display program with Max7219*/ dis[0] = (long int)pas / 10000000; dis[1] = (long int)pas % 10000000 / 1000000; dis[2] = (long int)pas % 1000000 / 100000; dis[3] = (long int)pas % 100000 / 10000; dis[4] = (long int)pas % 10000 / 1000; dis[5] = (long int)pas % 1000 / 100; dis[6] = (long int)pas % 100 / 10; dis[7] = (long int)pas % 10; Write_Max7219(8, dis[0]); Write_Max7219(7, dis[1]); Write_Max7219(6, dis[2]); Write_Max7219(5, dis[3]); Write_Max7219(4, dis[4]); Write_Max7219(3, dis[5]); Write_Max7219(2, dis[6]); Write_Max7219(1, dis[7]); Delay_xms(100); //delay 100ms }}