L3G4200D随机尖峰

大家好，



我正在使用a.m.陀螺仪研究倾角传感器。我在数字值中遇到随机峰值 - @ still device。


尖峰通常高于信号+255或低于平均信号-255。
它基本上发生在所有3轴上。特别是当平均信号大约为0时！


在我看来 - 芯片中存在一个问题，例如在读取特定16位值的低字节时不锁定Hi字节以保持Hi和Lo字节一致。所以我最终会读取“旧”值的Lo Byte和“new”值的Hi Byte。
这可能看起来像：


旧值：0xFFFF（-1）
新值：0x0002（+2）
组合错误读数：00FF（+255） - 如上所述，差异大约为255


数据表无济于事，因为它没有说明锁定机制或读取Hi和lo字节的特殊顺序 - 或者对状态位的依赖性。


我尝试了很多不同的设置 - 比如单字节和多字节读取 - Hi字节优先，Lo字节优先....
官方ST驱动程序首先是Lo字节，读取多个字节时的增量模式读取Lo字节，然后是Hi字节。


对于100hex边界附近的所有值，可以预期上述行为，但当然在无旋转条件下最明显。


我在网上搜索了类似的问题，并发现了一些具有完全相同的行为。


我将尝试直接访问ST产品专家，并在有新闻后更新此帖子。


任何想法或经验？


问候WOLF



以下为原文




Hi all,



i'm currently working on an inclination sensor using a.m. gyroscope. I encounter random spikes in the digital values - @ still device.


The spikes generally are either +255 above signal or -255 below average signal.
It basically happens on all 3 axis. Especially when the average signal is around 0!


In my opinion - there is a problem in the chip like NOT LOCKING the Hi byte when reading the Lo Byte of a particular 16 bit value to keep Hi and Lo Byte consistent. So i'm ending up reading the Lo Byte of the ''old'' value and the Hi Byte of the ''new'' value.
This might look like:  


old value: 0xFFFF (-1)
new value: 0x0002 (+2)
combined wrong Reading: 00FF (+255) - making a difference of about 255 as stated above


The data sheet won't help, as it doesn't say anything about a locking mechanism or a special order in reading Hi and lo Bytes - or a dependency on status bits.


I tried many different setups - like single and multi byte reading - Hi byte first, Lo byte first....
The official ST drivers are Lo byte first, and the increment mode when reading multiple bytes reads Lo byte and then Hi byte too.


Above behaviour is to be expected for all values neighbouring a 100hex border, but of course is most noticable in the no rotation condition.


I searched the web for similar problems and found a few with exactly the same behaviour.


I'll try to get a direct access to an ST product specialist and will update this post once there is news.


Any ideas or experiences?


Greetings WOLF