cc2500读取的RSSI值为什么不会变？

只看该作者 · 2014-9-24 17:15

cc2500寄存器的配置如下：
const RF_SETTINGS rfSettings = {
0x07, // FSCTRL1 Frequency synthesizer control.
0x00, // FSCTRL0 Frequency synthesizer control.
0x5D, // FREQ2    Frequency control word, high byte.
0x93, // FREQ1    Frequency control word, middle byte.
0xB1, // FREQ0    Frequency control word, low byte.
0xC8, // MDMCFG4 Modem configuration.
0x93, // MDMCFG3 Modem configuration.
0x73, // MDMCFG2 Modem configuration.
0x22, // MDMCFG1 Modem configuration.
0xF8, // MDMCFG0 Modem configuration.
0x00, // CHANNR Channel number.
0x01, // DEVIATN Modem deviation setting (when FSK modulation is enabled).
0xB6, // FREND1 Front end RX configuration.
0x10, // FREND0 Front end RX configuration.
0x00, // MCSM1    Main Radio Control State Machine configuration.
0x18, // MCSM0    Main Radio Control State Machine configuration.
0x1D, // FOCCFG Frequency Offset Compensation Configuration.
0x1C, // BSCFG    Bit synchronization Configuration.
0xC7, // AGCCTRL2  AGC control.
0x00, // AGCCTRL1  AGC control.
0xB0, // AGCCTRL0  AGC control.
0xA9, // FSCAL3 Frequency synthesizer calibration.
0x0A, // FSCAL2 Frequency synthesizer calibration.
0x00, // FSCAL1 Frequency synthesizer calibration.
0x11, // FSCAL0 Frequency synthesizer calibration.
0x59, // FSTEST Frequency synthesizer calibration.
0x88, // TEST2    Various test settings.
0x31, // TEST1    Various test settings.
0x0B, // TEST0    Various test settings.
0x07, // FIFOTHR RXFIFO and TXFIFO thresholds.
0x29, // IOCFG2 GDO2 output pin configuration.
0x06, // IOCFG0D GDO0 output pin configuration. Refer to SmartRF?Studio User Manual for detailed pseudo register explanation.
0x04, // PKTCTRL1  Packet automation control.
0x05, // PKTCTRL0  Packet automation control.
0x00, // ADDR    Device address.
0xFF // PKTLEN Packet length.
};
接收数据的代码如下：
BOOL CC2500_ReceivePacket(u8 *rxBuffer, u8 length)
{
u8 status[2];
u8 packetLength;

if (GDO0_detected  == 0)
{
      return FALSE;                            //没有收到数据，退出
}

GDO0_detected--;

if ((CC2500_ReadStatus(RXBYTES) & BYTES_IN_RXFIFO))
{
      packetLength = CC2500_ReadReg(RXFIFO);
      // Read data from RX FIFO and store in rxBuffer
      if (packetLength <= length)
      {
         CC2500_ReadBurstReg(RXFIFO, rxBuffer, packetLength);

         // Read the 2 appended status bytes (status[0] = RSSI, status[1] = LQI)
         CC2500_ReadBurstReg(RXFIFO, status, 2);
         RCV_RSSI = status[0];                         // <------这个值永远是0x02
         rssi = CC2500_ReadReg(RSSI_IND);             // <------这个值永远是0x5F

         CC2500_SendCmd(SIDLE);
         // Flush RX FIFO
         CC2500_SendCmd(SFRX);
         CC2500_SendCmd(SRX);       //置为接收
         // MSB of LQI is the CRC_OK bit
         return (status[1] & CRC_OK);
      }
      else
      {
         CC2500_SendCmd(SIDLE);
         CC2500_SendCmd(SFRX);
         CC2500_SendCmd(SRX);          //置为接收
         return FALSE;
      }
}
else
      return FALSE;
}
然后，我每次读出来的RSSI的值总是固定的，紧接着Data field的那个值永远是0x02，直接读RSSI寄存器，永远是0x5F，不管拿远拿近，或是换一块cc2500，值都不会变。

有谁能告诉我，这是怎么一回事？？