请教一下关于SPI操作NRF2401的奇怪现象.

wkong501

<div>(程序在下方)<br />
<div>我利用STM32的SPI控制NRF2401,在读寄存器时总是只能读到NRF的状态寄存器值0x0E, 而读不到指定寄存器(0x00配置寄存器)的值. 在调试时我发现, 用JTAG 执行到断点1(下方标出)再执行到断2, 可以成功读到数据. 全部执行则读取不到第二个数据. 按之前的经验一般调试模式成功,实际操作失败大多是时序问题,我试着在很多地方加入延时函数, 还是无法解决.</div>
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请原子大哥帮忙看一下.<br />
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u8 NRF2401_RdReg(u8 addr)</div>
<div>{</div>
<div><span class="Apple-tab-span" style="white-space:pre;">        </span>u8 rxfifo;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; //此前已将CE=0 CS=1 NRF开机等待100us.</div>
<div><span class="Apple-tab-span" style="white-space:pre;">        </span>NRF2401_ResetCS();</div>
<div><span class="Apple-tab-span" style="white-space:pre;">        </span>while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);<span class="Apple-tab-span" style="white-space:pre;">        </span> &nbsp;//等待缓冲空<span class="Apple-tab-span" style="white-space:pre;">        </span> &nbsp; !!!死循环危险</div>
<div><span class="Apple-tab-span" style="white-space:pre;">        </span>SPI_I2S_SendData(SPI1, addr);</div>
<div><span class="Apple-tab-span" style="white-space:pre;">        </span>while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);<span class="Apple-tab-span" style="white-space:pre;">        </span> &nbsp; //<span class="Apple-tab-span" style="white-space:pre;">        </span>!!!</div>
<div>断1<span class="Apple-tab-span" style="white-space:pre;">        </span>SPI_I2S_SendData(SPI1, 0x00);<span class="Apple-tab-span" style="white-space:pre;">                                                                        </span> &nbsp; //随机发送一个数,以接收寄存器内容</div>
<div>&nbsp; &nbsp; &nbsp; &nbsp; while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);<span class="Apple-tab-span" style="white-space:pre;">                </span>//RXNE=1;接收为空,即未接收到数据; &nbsp;!!!&nbsp;</div>
<div>断2<span class="Apple-tab-span" style="white-space:pre;">        </span>rxfifo = SPI1-&gt;DR;</div>
<div><span class="Apple-tab-span" style="white-space:pre;">        </span>NRF2401_SetCS();</div>
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<div><span class="Apple-tab-span" style="white-space:pre;">        </span>return rxfifo;</div>
<div>}</div>

wkong501

找到错误了,&nbsp;第一次接收后RXNE未清空

bingge191

回复【2楼】wkong501:
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<br>你用到是NRF24L01+还是以前的NRF2401AG模块？stm32控制nrf2401AG好像很不好处理。用SPI好像不能通信！！