Question

我很难通过I2C从Arduino接收负数。

我可以毫无问题地得到正整数，但是到目前为止，负整数和浮点数已经不在了。

C ++代码

//Declare and Include the necessary header files
#include <iostream>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/i2c-dev.h>
#include <sys/ioctl.h>
#include <fcntl.h>

//Define Address of Slave Address
#define ADDRESS 0x08

//Eliminate the Used of std in the future
using namespace std;

static const char *devName="/dev/i2c-1";

int main()
{
    //Check to see if C++ works
    cout<<"Hello, World!\n";
    cout<<"I2C: Connecting"<<endl;
    int file;

    if ((file = open(devName, O_RDWR))<0)
    {
        fprintf(stderr, "I2C: Failed to access");
        exit(1);
    }

    if (ioctl(file, I2C_SLAVE, ADDRESS)<0)
    {
        cout<<"Failed to Access"<<endl;
    }
    char buf[7];
    float dist1;
    int AcZ;
    short AcX;
    int AcY;

    for (int i=0;i<=100;i++){
        read(file,buf, 7);
        dist1=buf[0]<<8|buf[1];
        AcZ=buf[2]<<8 | buf[3];
        AcY=buf[4]<<8 | buf[5];
        AcX=buf[6]<<8 | buf[7];
        cout<<"To See"<<endl;
        cout<<buf[4]<<"   "<<buf[5]<<endl;
        cout<<"UltrasonicDistance"<<endl;
        cout<<"Distance 1: "<<dist1<<" cm"<<endl;
        cout<<" "<<endl;
        cout<<"Acceleration"<<endl;
        cout<<"X Direction: "<<AcX<<endl;
        cout<<"Y Direction: "<<AcY<<endl;
        cout<<"Z Direction: "<<AcZ<<endl;
        //cout<<f11<<endl;
        usleep(2000000);
        cout<<" "<<endl;
    }
    return 0;
}

Arduino代码

//Declare Needed header file
#include <Wire.h>

//Declare the pins
#define echoPin 7
#define trigPin 8

//Define Accelerometer Address
const int MPU=0x68;

uint32_t timer=millis();

//Declare Accelerometer Variable
int16_t AcX,AcY,AcZ,Tmp,GyX,GyY,GyZ;

float f1= 1.123214324532514;
byte *fp = (byte *) &f1;

//Declare the ultrasonic variables
long duration;
long distance;
void setup()
{
  //Join I2C bus as Slave with Address 8;
  Wire.begin (8);

  //Call SendData Command
  Wire.onRequest(SendData);

  //Setup Pins as output and input to operate ultrasonic sensor
  pinMode(echoPin, INPUT);
  pinMode(trigPin, OUTPUT);

  //Setup for Accelerometer Sensor
  Wire.beginTransmission(MPU);
  Wire.write(0x6B);
  Wire.write(0);
  Wire.endTransmission(true);
  //Begin Serial Monitor

  Serial.begin (9600);
}

void loop ()
{
    dist();
    GY521();
    delay(2000);
}
//Obtain Ultrasonic Data
void dist()
{
  digitalWrite (trigPin,LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin,HIGH);
  delayMicroseconds(2);
  digitalWrite(trigPin,LOW);
  duration=pulseIn(echoPin,HIGH);
  distance=duration/58.2;
  Serial.print(distance);
  Serial.println(" cm");
}
//Obtain Accelerometer Data
void GY521()
{
  Wire.beginTransmission(MPU);
  Wire.write(0x3B);
  Wire.endTransmission(false);
  Wire.requestFrom(MPU,12,true);
  AcX=Wire.read()<<8|Wire.read();
  AcY=Wire.read()<<8|Wire.read();
  AcZ=Wire.read()<<8|Wire.read();
  GyX=Wire.read()<<8|Wire.read();
  GyY=Wire.read()<<8|Wire.read();
  GyZ=Wire.read()<<8|Wire.read();

  Serial.println("Accelerometer: ");
  Serial.print("X= "); Serial.println(AcX);
  Serial.print("Y= "); Serial.println(AcY);
  Serial.print("Z= "); Serial.println(AcZ);

  Serial.print("f1= ");
  Serial.print(fp[0], HEX);
  Serial.print(fp[1], HEX);
  Serial.print(fp[2], HEX);
  Serial.print(fp[3], HEX);
  Serial.println();

}

void SendData()
{
  byte test[]={distance>>0x8,distance,AcZ>>0x8, AcZ,AcY>>8,AcY,AcX>>8,AcX};
  Wire.write(test,8);
}

对于“加速度值”，它可以是负值，如果负值浮出水面，我需要接收，但是我只能得到大约65000的数字

我想使用CPP从Arduino接收浮点数和负数

0 个答案: