STPM33 IC SPI光耦合器数据读取包含CRC错误

您确定SPI时钟速率对耦合器而言不是太快吗？
 
您可以通过适当的GPIOx_OSPEEDR寄存器（稍微）影响边沿速率。
 
看到输入和输出的范围痕迹会很有趣。光耦合器的输出。



以下为原文

Are you sure the SPI clock rate isn't just too fast for the coupler?

You can affect the edge rates (somewhat) via the appropriate GPIOx_OSPEEDR register.

It'd be interesting to see scope traces of the input & output of the optocoupler.

为确保SPI时钟以2kHz运行......我们是否也可以改变SPI线的边沿速率？
 
随着6n137，40ns的上升时间，27ns的下降时间，我们得到了光耦合器o / p。还有一个175-200mV的偏移（当光耦合器o / p为低电平时，它将为175mV左右）



以下为原文

To ensure that ,SPI clock is running at 2kHz... Whether we can change edge rates of SPI lines also?

With 6n137 , 40ns rise time , 27ns fall time we are getting at optocoupler o/p. Also there is a 175-200mV offset ( When optocoupler o/p is LOW, it will be around 175mV)

我认为偏移可能没有帮助。



以下为原文

I'd think the offset is probably not helpful.

6n137具有显着的辐射二极管电容，这使得导通延迟，并且还允许其在释放电压后发光。
有必要为二极管提供双向电流。为此，将电阻器并联连接到二极管的触点，并计算流过它的工作电流。该电流的加倍值必须流过淬火电阻，并连接到低功率的换向场效应晶体管。
偏移由第三电阻器设置，并联到换向晶体管。当二极管开关电压最小时，初始偏移量在最高温度下计算。
这里有很多单词，但你会有更多的纸张计算。祝你好运。



以下为原文

6n137 has a significant capacitance of a radiating diode, which makes the on-delay, and also allows it to glow after relieving the voltage.
It is necessary to provide a bi-directional current flow for the diode. To do this, connect the resistor in parallel to the contacts of the diode, with the calculation of the operating current flowing through it. The doubled value of this current must flow through the quenching resistor, with connection to a commutating field-effect transistor of low power.
The offset is set by a third resistor, with a parallel connection to the commutating transistor. The initial offset is calculated at the maximum temperature when the diode on-off voltage is at a minimum.
There are many words here, but you will have even more paper calculations. Good luck.