BHI260 - Calibration State - BSX Algorithm Parameters

Hi,

I'm working with a BHI260 chip. As a host, I'm using an STM32L433 microcontroller. I don't use the BHY API on the host, I've written my own communication code.

I've successfully uploaded the firmware to the BHI, and I'm also successfully getting the Gravity and Game Rotation Vector measurements at 25Hz.

Now I want to get the calibration state of the accelerometer and the gyroscope. According to the datasheet, to get that information I have to send the Get Parameter Status Command (Section 13.3 in the datasheet) following the Host Command Protocol (Section 4.4 in the datasheet).

The parameters that I have to read are 0x0201 and 0x0203 as shown below:

As indicated in the 3rd column of the table, the accelerometer, and gyroscope content is returned inside a BSX State Exchange Structure. According to the datasheet, this is the format:

So, If I send the Parameter Status Command [0x1201] (The first "1" of the 0x1201 os for indicating the "Read" operation) I should expect to get the calibration state value of the accelerometer within the Block data of the BSX State Exchange Structure sent by the BHI chip on the response of my command (taken from the Status and Debug FIFO).

But unfortunately, in the datasheet, there's no definition of how's the data arranged within the Block data. So I don't know exactly which byte of the Block Data is telling me the calibration state of the accelerometer.

Here I have the real measurements. I send the Parameter Status Command [0x1201] and I get the following data from the BHI chip:

BlockData[0]:   0x1	
BlockData[1]:   0x50	
BlockData[2]:   0x0	
BlockData[3]:   0x4	
BlockData[4]:   0x7f	
BlockData[5]:   0x90	
BlockData[6]:   0x1	
BlockData[7]:   0x40	
BlockData[8]:   0x6	
BlockData[9]:   0x0	
BlockData[10]:  0x6f	
BlockData[11]:  0x0	
BlockData[12]:  0x0	
BlockData[13]:  0x0	
BlockData[14]:  0xff	
BlockData[15]:  0x0	
BlockData[16]:  0x0	
BlockData[17]:  0x0	
BlockData[18]:  0xb	
BlockData[19]:  0x0	
BlockData[20]:  0x10	
BlockData[21]:  0x0	
BlockData[22]:  0x0	
BlockData[23]:  0x1	
BlockData[24]:  0x0	
BlockData[25]:  0x0	
BlockData[26]:  0x0	
BlockData[27]:  0x0	
BlockData[28]:  0x0	
BlockData[29]:  0x0	
BlockData[30]:  0x0	
BlockData[31]:  0x0	
BlockData[32]:  0x0	
BlockData[33]:  0x0	
BlockData[34]:  0xb	
BlockData[35]:  0x0	
BlockData[36]:  0x8	
BlockData[37]:  0x0	
BlockData[38]:  0x0	
BlockData[39]:  0x4	
BlockData[40]:  0x0	
BlockData[41]:  0x0	
BlockData[42]:  0xb	
BlockData[43]:  0x0	
BlockData[44]:  0x58	
BlockData[45]:  0x0	
BlockData[46]:  0x0	
BlockData[47]:  0x9	
BlockData[48]:  0x0	
BlockData[49]:  0x0	
BlockData[50]:  0x0	
BlockData[51]:  0x0	
BlockData[52]:  0x0	
BlockData[53]:  0x0	
BlockData[54]:  0x0	
BlockData[55]:  0x0	
BlockData[56]:  0x0	
BlockData[57]:  0x0	
BlockData[58]:  0x0	
BlockData[59]:  0x0		
BlockData[60]:  0x0		
BlockData[61]:  0x0		
BlockData[62]:  0x0		
BlockData[63]:  0x0

Which of the Block Data bytes (0 to 63) contains the accelerometer calibration state?

Thanks!

Best reply by BSTRobin

Hello btruden_henway,

I know that what you want to do. But the calibration state and SIC matrix use a BSX internal binary data format and are not intended to be interpreted by the host.

Normally, the following are general usage methods:

1. Calibrate sensors(accel, gyro, mag) until the accuracy of all sensors is 3;

2.get sensor calibration status;

3.set sensor calibration.

In fact, you don't have to care about the content of calibration profile, just need to care about get and set.

BSX STATE EXCHANGE STRUCTURE

BSX ALGORITHM

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