LIS2DH12 SPI通信：设备交替回答FF

你好，
我目前正在测试安装在MKI151V1上的LIS2DH12加速度计。该板连接到NI的SPI / I2C设备，因为我想将传感器集成到labview测量软件中。首先，我想提一下，我是一个使用SPI的初学者，所以我可能犯了一个简单的错误。
在LabVIEW中，我首先打开SPI配置（设置片选，时钟速率，时钟极性，时钟相位），然后是读/写命令。在通信结束时，我再次关闭SPI配置。相应的R / W LabVIEW-VI需要一个十六进制数组作为输入，并在必要时以十六进制数组输出返回SPI从设备的答案。
LIS2DH12的每个命令都包含8位。因此，每个数组索引代表一个字节（十六进制格式）。
在读取的情况下，第一个数组索引表示读取命令（RW位; MS位;寄存器地址）。以下数组索引必须是我想要接收的寄存器数据的可选十六进制数。
在写入的情况下，第一个索引表示写入命令，以下索引表示我想在寄存器中写入的数据。
例如，当我想读取寄存器'WHO_AM_I'（0Fh）时：我发送输入数组'8Fh; 00h'（索引0;索引1）并接收输出数组'8Fh; 33h'，这是正确答案这个登记册。到目前为止，一切正常。
最后我会谈到实际问题。如果我重复此读取命令，加速度计将以“FFh”回答。无论多个R / W命令之间的时间是什么，来自任何寄存器的每个R / W命令都会出现此问题。当我第一次连接传感器时，它也会响应'FFh'。
您有任何想法，这种行为的原因是什么？
有没有人有使用NI的SPI / I2C设备的经验？
我想提前感谢你。
最好的祝福，
帕斯卡尔

#lis2dh12＃spi-communication #labview



以下为原文




Hello,
I'm currently testing the LIS2DH12 accelerometer, which is mounted on the MKI151V1. The board is connected to a SPI/I2C device from National Instruments because I want to integrate the sensor in a LabVIEW measurement software. First of all, I would like to mention, that I'm a beginner in working with SPI, so it is possible that I make a simple mistake.
In LabVIEW, I first open a SPI configuration (Set Chip Select, Clock Rate, Clock Polarity, Clock Phase) followed by the Read/Write Command. At the end of the communication, I close the SPI configuration again. The corresponding R/W LabVIEW-VI needs an hex-array as input and returns the answer of the SPI-Slave, if necessary, in an hex-array output.
Every command of the LIS2DH12 consists of 8bit. Thus every array index represents one byte (hex format).
In case of a reading, the first array index represents the read command (RW bit; MS bit; register address). The following array indices have to be an optional hex-number for the number of register data I want to receive.
In case of a writing, the first index represents the write command and the following indices represent the data I want to write in the register/s.
As an example, when I want to read register 'WHO_AM_I' (0Fh): I send the input array '8Fh;00h' (index 0; index 1) and receive the output array '8Fh;33h', which is the right answer for this register. So far, everything works fine.
Finally I will come to the actual problem. If I repeat this read command the accelerometer answers with 'FFh'. This problem occurs with every R/W-command from any register, no matter what time is in between multiple R/W-commands. When I connect the sensor for the first time, it also responds with 'FFh'.
Do you have any ideas what the reason for this behavior is?
Does anyone have some experience in working with the SPI/I2C device from National Instruments?
I would like to thank you in advance.
Best Regards,
Pascal

#lis2dh12 #spi-communication #labview