ADXL345在正确得到ID后无法获取XYZ数据是为什么？

我芯片用的是realtek公司的蓝牙芯片，内核是ARM Cortex-M0。接线采用的是4线制的spi
我现在能获取到正确的ID值，但是在获取XYZ值时候返回的都是0；初始化程序如下
请教哪里有问题
void ADXL345_write_byte(uint8_t addr,uint8_t data)
{
   uint8_t sendBuf[2];
   sendBuf[0]=addr|0xC0;
   sendBuf[1]=data;
   //DBG_DIRECT("RegAddr=0x%2x",sendBuf[0]);
   SPI_SendBuffer(SPI0, sendBuf, 2);
x
void ADXL345_Ini(void)
{
   ADXL345_write_byte(0x31,0x2B);
   delayMS(2);
   ADXL345_write_byte(0x1E,0x00);
   delayMS(2);
   ADXL345_write_byte(0x1F,0x00);
   delayMS(2);
   ADXL345_write_byte(0x20,0x00);
   delayMS(2);
   ADXL345_write_byte(0x21,0x00);
   delayMS(2);
   ADXL345_write_byte(0x22,0x00);
   delayMS(2);
   ADXL345_write_byte(0x23,0x00);
   delayMS(2);
   ADXL345_write_byte(0x24,0x01);
   delayMS(2);
   ADXL345_write_byte(0x25,0x01);
   delayMS(2);
   ADXL345_write_byte(0x26,0x2B);
   delayMS(2);
   ADXL345_write_byte(0x27,0x00);
   delayMS(2);
   ADXL345_write_byte(0x28,0x09);
   delayMS(2);
   ADXL345_write_byte(0x29,0xFF);
   delayMS(2);
   ADXL345_write_byte(0x2A,0x80);
   delayMS(2);
   ADXL345_write_byte(0x2C,0x0D);
   delayMS(2);
   ADXL345_write_byte(0x2D,0x08);
   delayMS(2);
   ADXL345_write_byte(0x2E,0x80);
   delayMS(2);
   ADXL345_write_byte(0x2F,0x00);
   ADXL345_write_byte(0x38,0x00);
   delayMS(2);
}