STM32 SPI: MPU9250 IMU detailed guidance

This video shows how to configure SPI to communicate with the MPU9250 IMU sensor.
A code is available on: github.com/Ste...
Visit the website to learn the Orientation Estimation using STM32 MCU and IMU sensor:
www.steppescho...
Datasheet MPU9250:
invensense.tdk...
Register map:
invensense.tdk...
0:00 Introduction
0:12 Configure SPI using STM32Cubemx software
1:26 Timer interrupt explanation
2:26 Reading IMU measurements using SPI
7:09 Plotting data using the timeline graph
8:12 Changing the accelerometer full-scale range by transmitting data through SPI
11:17 Further improvements

[@camilolopezcalvache6205]

I from Colombia, I watch your videos about imu sensors. I would like You to continue with the imu icm sensor configuration series.

[@steppeschool3629]

Hi,
I appreciate your interest in my channel. Soon, I will release new videos about the ICM-20948 sensor. If you have not subscribed, do not forget to subscribe to avoid missing out on new videos. Also, you can get up-to-date info and source code on my Patreon page:
www.patreon.com/user?u=80399744

[@onyinyechichukwuma689]

Very helpful. Thanks :)

[@steppeschool3629]

Glad it was helpful!

[@arjunsivasankar1427]

hello sir, thank you very much for the videos you have posted till now/
could you please post a video on how to initialize the swv data tracking timeline graph, and how to use them for I2C connections as well.
that would be really helpful for my project.

[@bobby9568]

Very cool

[@steppeschool3629]

Thanks😀

[@rohitsinghbhadauria5543]

Hii,
I am using imu icm-42688 with stm32 nucleo-144 board. Here, i am trying to read WHO_AM_I register value but output i am getting is 0xFF or 0x0. I dont know what is going wrong

[@steppeschool3629]

Hi, Are you sure that the wirings are correct? Once you verify it, check the register address and other small details. Usually, the problem originates from a place you least expected

[@rohitsinghbhadauria5543]

Actually I got the output but it's not working on setting frequency of spi above 2Mhz

[@steppeschool3629]

Complete guidance on Euler angles and quaternions computation using IMU sensors can be found in my course:
www.steppeschool.com/courses/stm32-hal-orientation-estimation
The code is available on: github.com/Steppeschool/STM32-MPU9250-Example

[@jayarangarakesh4581]

For accessing the full scale range using mpu9250_write_reg() function, why are you sending the register without write bit? I could see you have just send 0x28 as address. Are you not sending the write bit because the write bit is "0"?

[@steppeschool3629]

Yes, you are right. The most significant bit is 0 for a write operation and '1' for read operation

[@intjengineering]

Could you please explain the prescaler that you use in the beginning of the video? Why did you choose that value, how does it affect the process?
Thanks.

[@steppeschool3629]

Hi,
The prescaler defines the speed (frequency) of the SPI protocol:
SPI speed = clock frequency / (prescaler + 1)
Usually, every chip has a maximum SPI speed it can support. Based on this info, you set the prescaler. However, if time is not critical, you can set higher prescaler to have lower speed.
Did I answer your question?

[@intjengineering]

@@steppeschool3629, you did. Thank you very much.
Greetings from 🇩🇪.

[@arjunsivasankar1427]

why did u perform this operation
uint8_t temp_data = 0x80|reg;
from did that 0x80 came ?

[@steppeschool3629]

Hi,
For a read operation, you have to set the most significant bit. That is why I added 0x80

[@rhamarn.6586]

Hello friend, my scale setting on the accelerometer is not working, it is only in 2g mode. MPU9250

[@steppeschool3629]

Hi,
What value did you set for register 28 (accelerometer configuration register)?

[@isaacclark9825]

Not sure if it matters to you, but this particular IMU, the MPU9250 is no longer manufactured. There are still some around.

[@steppeschool3629]

thanks for insightful information

[@shamssalehin2376]

I bought one board, thats fake ic