AD5933数据能够写入，但是无法读出，求解
STM32通过I2C读写AD5933数据， 用的是STM32的I2C1, 数据可以正常写入，测量AD5933可以产生激励信号，但是却读不回来数据，无论读哪个寄存器地址，读出来的都是0X1A。不知道是不是STM32的I2C读函数写错了，手册上写的读字节时序，最后一个位是非应答，这里有点不确定是怎么操作。 本帖最后由 areak 于 2014-12-30 18:42 编辑
void I2C_Pointer_Write(unsigned char reg_addr)
{
while(I2C_GetFlagStatus(I2C1,I2C_FLAG_BUSY));
I2C_GenerateSTART(I2C1,ENABLE);
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_MODE_SELECT));
I2C_Send7bitAddress(I2C1,0X1A,I2C_Direction_Transmitter);
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
I2C_SendData(I2C1,0XB0);
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_BYTE_TRANSMITTED));
I2C_SendData(I2C1,reg_addr);
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_BYTE_TRANSMITTED));
I2C_GenerateSTOP(I2C1,ENABLE);
}
char I2C_Byte_Read(unsigned char reg_addr)
{
char recieve_data;
I2C_Pointer_Write(reg_addr);
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));
/* Send START condition */
I2C_GenerateSTART(I2C1, ENABLE);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
I2C_Send7bitAddress(I2C1, 0X1B, I2C_Direction_Transmitter);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
/* Disable Acknowledgement */
I2C_AcknowledgeConfig(I2C1, DISABLE);
recieve_data = I2C_ReceiveData(I2C1);
I2C_GenerateSTOP(I2C1, ENABLE);
/* Enable Acknowledgement to be ready for another reception */
I2C_AcknowledgeConfig(I2C1, ENABLE);
return recieve_data;
}
这是读AD5933的函数。 怎么都没人回复的？ 本帖最后由 weizhongc 于 2014-12-31 11:18 编辑
{:1_99:}硬件的I2C,要不你先用模拟的试下啊。不然你改下你的读取函数，是最后一个字节读取时不要ack。不是所有读取操作都不要ACK
char I2C_Byte_Read(unsigned char reg_addr，unsigned char ack)
{
char recieve_data;
I2C_Pointer_Write(reg_addr);
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));
/* Send START condition */
I2C_GenerateSTART(I2C1, ENABLE);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
I2C_Send7bitAddress(I2C1, 0X1B, I2C_Direction_Transmitter);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
/* Disable Acknowledgement */
if(ack)
I2C_AcknowledgeConfig(I2C1, DISABLE);
else
I2C_AcknowledgeConfig(I2C1, ENABLE);
recieve_data = I2C_ReceiveData(I2C1);
I2C_GenerateSTOP(I2C1, ENABLE);
/* Enable Acknowledgement to be ready for another reception */
I2C_AcknowledgeConfig(I2C1, ENABLE);
return recieve_data;
}
已搞定，谢谢你
weizhongc 发表于 2014-12-31 11:04
硬件的I2C,要不你先用模拟的试下啊。不然你改下你的读取函数，是最后一个字节读取时不要ack。不是所有读取操作都不要ACK
char I2C_Byte_Read(unsigned char reg_addr，unsigned char ack)
{
char recieve_data;
I2C_Pointer_Write(reg_addr);
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));
/* Send START condition */
I2C_GenerateSTART(I2C1, ENABLE);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
I2C_Send7bitAddress(I2C1, 0X1B, I2C_Direction_Transmitter);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
/* Disable Acknowledgement */
if(ack)
I2C_AcknowledgeConfig(I2C1, DISABLE);
else
I2C_AcknowledgeConfig(I2C1, ENABLE);
recieve_data = I2C_ReceiveData(I2C1);
I2C_GenerateSTOP(I2C1, ENABLE);
/* Enable Acknowledgement to be ready for another reception */
I2C_AcknowledgeConfig(I2C1, ENABLE);
return recieve_data;
}解决了，程序问题，谢谢 <div class='shownolgin' data-isdigest='no'>什么问题啊areak 发表于 2014-12-31 15:22
解决了，程序问题，谢谢
</div><script>showreplylogin();</script><script type="text/javascript">(function(d,c){var a=d.createElement("script"),m=d.getElementsByTagName("script"),eewurl="//counter.eeworld.com.cn/pv/count/";a.src=eewurl+c;m.parentNode.insertBefore(a,m)})(document,523)</script> <div class='shownolgin' data-isdigest='no'>I2C_Send7bitAddress(I2C1, 0X1B, I2C_Direction_Transmitter);
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));低级错误，这两句写错了。I2C_Direction_Transmitter-->I2C_Direction_RecieverI2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED-->I2C_EVENT_MASTER_RECIRVER_MODE_SELECTEDweizhongc 发表于 2014-12-31 16:00
什么问题啊
</div><script>showreplylogin();</script> <div class='shownolgin' data-isdigest='no'>老哥还在么....虽然现在是2020年了，距离您发帖有6年，6年轻我还在参加中考哈哈哈，现在我在用AD5933，我怎么样都写不进去，因为我写入后读出来发现寄存器是空的，大佬如果能看到能给小弟发一下您的数据写入的函数吗，谢谢了我块搞了一个多月了，一直卡着没进展要哭了</div><script>showreplylogin();</script>
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