c - ADXL345只读ceros

我正在尝试使用能量将ADXL 345与tm4c1294nctpd配对，
引脚的配置是下一个
使用J1（3.3V）和J21（5V）以及GND的PB3引脚的SDA和PB2的SCL（I2C0端口）。
在ergya的串行监控下，输出为x = 0，y = 0，z = 0，
，电路在SDA和SCL引脚中具有上拉电阻，

传感器的地址为0x53。我了解我正在将该设备作为I2C协议的从设备（Wire.begin（ADXAddress）;）

该代码是

 #include "Wire.h"

#define Power_Register 0x2D
#define BW_rate 0x2C
#define Int_enable 0x2E
#define dataFormat 0x31
#define X_Axis_Register_DATAX0 0x32
#define X_Axis_Register_DATAX1 0x33
#define Y_Axis_Register_DATAY0 0x34
#define Y_Axis_Register_DATAY1 0x35
#define Z_Axis_Register_DATAZ0 0x36
#define Z_Axis_Register_DATAZ1 0x37
#define fifoCntrl 0x38

int ADXAddress = 0x53;
int X0,X1,X_out;
int Y0,Y1,Y_out;
int Z1,Z0,Z_out;
float Xa,Ya,Za;

void setup() {
  Wire.setModule(0);
  Wire.begin(ADXAddress);
  Serial.begin(9600);
  delay(100);
  Wire.beginTransmission(ADXAddress);
  Wire.write(Power_Register);
  Wire.write(8);
  Wire.write(BW_rate);
  Wire.write(10);
  Wire.write(dataFormat);
  Wire.write(11);
  Wire.write(fifoCntrl);
  Wire.write(0);

  Wire.endTransmission();


}


void loop() {

 Wire.beginTransmission(ADXAddress);
 Wire.write(X_Axis_Register_DATAX0);
 Wire.write(X_Axis_Register_DATAX1);
 Wire.endTransmission();
 Wire.requestFrom(ADXAddress,2);
 if(Wire.available()<=2) {
   X0 = Wire.read();
   X1 = Wire.read();
   X1=X1<<8;
   X_out =X0+X1;

 }

 Wire.beginTransmission(ADXAddress);
 Wire.write(Y_Axis_Register_DATAY0);
 Wire.write(Y_Axis_Register_DATAY1);
 Wire.endTransmission();
 Wire.requestFrom(ADXAddress,2);
 if(Wire.available()<=2) {
   Y0 = Wire.read();
   Y1 = Wire.read();
   Y1=Y1<<8;
   Y_out =Y0+Y1;
 }

 Wire.beginTransmission(ADXAddress);
 Wire.write(Z_Axis_Register_DATAZ0);
 Wire.write(Z_Axis_Register_DATAZ1);
 Wire.endTransmission();
 Wire.requestFrom(ADXAddress,2);
 if(Wire.available()<=2) {
   Z0 = Wire.read();
   Z1 = Wire.read();
   Z1=Z1<<8;
   Z_out =Z0+Z1;

 }

 Serial.print("Xa= ");
 Serial.print(Xa);Serial.print("\t");
 Serial.print("Ya= ");
 Serial.print(Ya);Serial.print("\t");
 Serial.print("Za= ");
 Serial.println(Za);


 delay(1000);
 Serial.println();
}

最佳答案

如果要写入随机I2C寄存器，则需要重新开始传输。只需创建一个函数即可简化此过程。

void writeReg ( int reg, int value )
{
    Wire.beginTransmission(ADXAddress);
    Wire.write(reg);
    Wire.write(value);
    Wire.endTransmission();
}

void setup()
{
  Wire.setModule(0);
  Wire.begin(ADXAddress);
  Serial.begin(9600);
  delay(100);

  writeReg(Power_Register,8);
  writeReg(BW_rate,10); // <-- should this be 0x10 ?
  writeReg(dataFormat,11); // <-- should this be 0x11 ?
  writeReg(fifoCntrl,0);  // <-- this isn't strictly needed as fifoCntrl will be 0 at power on reset anyway

}

其次，您使用的教程（我已经在网上看到）实际上不是100％正确的。读取寄存器时，它只能写入一个字节-读取前不能写入两个字节，一次只能设置寄存器指针。简化代码以提供另一个阅读功能，以使代码更易于阅读。

int readAxis ( int reg )
{
   Wire.beginTransmission(ADXAddress);
   Wire.write(reg);
   Wire.endTransmission();
   Wire.requestFrom(ADXAddress,2);

   int d0 = Wire.read();
   int d1 = Wire.read();

   return (d1<<8) + d0;
}

void loop ()
{
    X_out = readAxis(X_Axis_Register_DATAX0); // this will read TWO bytes starting from X0 register (LSB + MSB)
    Y_out = readAxis(X_Axis_Register_DATAY0);
    Z_out = readAxis(X_Axis_Register_DATAZ0);
    :

第三，您实际上并没有打印任何内容，因为您忘记设置Xa，Ya和Za值

:

Xa = (float)X_out/RANGE;
Ya = (float)Y_out/RANGE;
Za = (float)Z_out/RANGE;


Serial.print("Xa= ");
Serial.print(Xa);Serial.print("\t");
Serial.print("Ya= ");
Serial.print(Ya);Serial.print("\t");
Serial.print("Za= ");
Serial.println(Za);

您需要根据所选ADXL输出的满量程（以G为单位）定义RANGE。请检查您的操作模式下的ADXL数据表（即2 G或16 G操作等...每个的满量程值是多少？）

#define ADXL_FULLSCALE 4096   // 2^(13 bits- 1 signed bit)
#define ADXL_FULLSCALE_G 16   // +/- 16 G operation
#define RANGE (ADXL_FULLSCALE /ADXL_FULLSCALE_G )

关于c - ADXL345只读ceros，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/58584996/