Posted on July 16, 2018 at 21:05I am working with the datalog application of the sensortile evaluation kit. I can see the data collected from the the acc (LSM303AGR), gyro(LSM6DSM), and mag(LSM303AGR). I have read the data sheet of these sensors, but still have no idea about how to interpret the data. In particular, I have the following questions (by the way, I asked the same questions to support and had not got any response for more than a week.):
(1) acc and gyro data: How do I interpret the acc and gyro data in terms of the units (g for acc, degree/sec for gyro). For example, one sample data I got is
acc = {axis_x, axis_y, axis_z} = { 80, 144, 993},
gyro = {axis_x, axis_y, axis_z} = {-280, 3150, -1050}
How do I translate that in terms of g and d/s?
(2) mag data: I am not clear how to interpret the data in terms of the direction of motion with respect of the north pole (that was my understanding of a e-compass).
For example,
mag = {axis_x, axis_y, axis_z} = {244, 189, -648}
I have no idea how to read the data.
(3) x, y, z axis of the data: Suppose I put the board (and sensor) facing up, I assume the z-axis is vertical to the earth and points up, x-axis and y-axis is parallel to the earth. But which direction is x and which direction is y?
(4) In sensortile_accelero.c, have some questions about the following APIs
BSP_ACCELERO_SET_FS
BSP_ACCELERO_SET_ODR
---- I do not see them being called for datalog application (only accelerometer init and enable are called). How are they (full scale, sample, rate ) set, then? Maybe there is a default setup for full scale and data rate? The reason I am asking is if I want know how to change the full scale and data rate.
BSP_ACCELERO_SET_AXIS_STATUS,
----I looked and the code, it says 'Set the enabled/disabled status of the accelerometer sensor axes',
what is the 'status' of an axis?
BSP_ACCELERO_Get_6D_Orientation_XH_Ext (and XL, YH, YL,....)
--- the code says: Get the 6D orientation XH axis. What does 'Orientation' mean here. How do I interpret the data from the APS, can you give me an example?
BSP_ACCELERO_Get_Sensitivity
---- What does the 'sensitivity' mean here
Thanks in advance for your help. A good tech note with examples would be greatly appreciated.
Jin
null
