MPU9250 Digital Motion Processor is a multi-purpose processor introduced by Asahi Kasei Microdevices Corporation. The MPU9250 is a 9-axis Motion Tracking device with a 3-axis accelerometer, 3-axis magnetometer, and a 3-axis gyroscope integrated into a small compact IC. The DMP has three 16-bit resolution analog-to-digital Converters for the digitization of the outputs from the accelerometer, magnetometer, and gyroscope. The device also has a separate power supply for digital I/O, an integrated temperature sensor, and programmable interrupts.
Table of Contents
MPU9250 Communication Interfaces
The MPU9250 processor has an I2C interface for serial data communication at the rate of 400 kHz. For faster communication, it also supports a Serial Peripheral Interface (SPI) with a rate of up to 20MHz. The DMP is also provided with the auxiliary I2C protocol to communicate with non-inertial sensors such as pressure sensors, etc.
This tutorial will share the pin configuration, features, specification, interfacing, and applications.
The following diagram shows the pinout of the MPU9250 9-axis Digital Motion Processor:
MPU9250 9-axis Digital Motion Processor chip has a total of 24 pins but only 10 of them are extended to the board. The pin configuration detail in tabular is mentioned below:
|2-6, 14-17||NC||Not Connected|
|1||RESV||Reserved. VDDIO connection pin|
|7||AUX-CL||I2C Master Serial Clock for external sensors connection pin|
|8||VDDIO||Digital I/O Power Supply pin|
|9||AD0/SDO||I2C LSB Address/Serial data out pin|
|10||REGOUT||Regulator Filter Connection pin|
|11||FSYNC||Frame Synchronization input pin|
|13||VDD||Power supply pin|
|19||RESV||Reserved. Not connected|
|20||RESV||Reserved. Ground Connection pin|
|21||AUX-DA||I2C Serial Data input for external sensors connection pin|
|22||nCS||Chip selection pin|
|23||SCL/SCLK||I2C Serial Clock/SPI Serial Clock pin|
|24||SDA/SDI||I2C Serial Data/SPI Serial Data pin|
- Auxiliary I2C Interface: This interface is used for off-chip sensor communication. It has two modes i.e.I2C Master mode and Pass-Through mode.
- Frame Synchronization: It is used to synchronize data frames in case of data transmission errors.
- I2C: Inter-Integrated Circuit is a half-duplex interface for serial communication.
- SPI: Serial Peripheral Interface is a full-duplex high-speed protocol for serial transmission.
- VDDIO: A supply pin for digital input/output pins.
MPU9250 Features and Specifications
Following are some of the features of the MPU 9-axis DMP:
|Features and Peripherals||Availability|
|SPI Data Rate||1 Mhz|
|SPI Fast Data Reading Rate||20 Mhz|
|I2C Data Rate||400 kHz|
|FIFO buffer||512 Bytes|
|Auxiliary I2C interface||1|
|Operating Voltage||2.4-3.6 Volts|
|Digital Output Temperature Sensor||Yes|
|User-Programmable Digital Filters||Yes|
- It has a triple-axis MEMS gyroscope
- Digital-output X-, Y-, and Z-Axis angular rate sensors (gyroscopes) with a user-programmable full-scale range of ±250, ±500, ±1000, and ±2000°/sec
- It comes with three 16-bit Analog-to-Digital Converters
- It has a low-pass filter that is digitally-programmable
- Operating current: 3.2mA
- Sleep mode current: 8µA
- Factory calibrated sensitivity scale factor
- It has a triple-axis MEMS accelerometer
- Digital-output triple-axis accelerometer with a programmable full-scale range of ±2g, ±4g, ±8g, and ±16g
- It also has three inbuilt analog-to-digital converters with 16-bit resolution
- Operating current: 450µA
- Low power operating current: 8.4µA at 0.98Hz, 19.8µA at 31.25Hz
- Sleep mode operating current: 8µA
- User-programmable interrupts
- It also comes with a wake-on-motion interrupt for low power operation of applications processor
- It is a triple-axis MEMS magnetometer
- 3-axis silicon monolithic Hall-effect magnetic sensor with magnetic concentrator
- It comes with a wide dynamic range and high resolution with low current consumption.
- The output data resolution is 14 bit (0.6µT/LSB)
- It has a full-scale measurement range of ±4800µT
- Normal operating current: 280µA
- Repetition Rate: 8Hz
- Self-test function with an internal magnetic source to confirm magnetic sensor operation on end products
MPU9250 Block Diagram
The block diagram of the Digital Motion Processor showing the connectivity of the processor and peripherals is as follows:
How to Interface MPU9250 DMP With Microcontroller?
The interfacing of the MPU9250 DMP with any microcontroller is shown in the diagram below:
- Microcontroller must have at least one either SPI or I2C serial protocol in order to interface with the module.
- The module is powered through the power supply pins
- Connect the analog pins of the microcontroller to the Serial data line (SDA) and Serial clock line (SCA). The transmission will take place through the I2C protocol.
- The module has a Serial Peripheral Interface as well for communication purposes.
- Make sure to add pull up resistors to avoid I2C signal loss, if the concerned microcontroller does not use any.
- Motion-based game controllers
- 3D remote controls for Internet-connected DTVs and set-top boxes, 3D mice
- Wearable sensors for health, fitness and sports
- Location based services, points of interest, and dead reckoning
- Handset and portable gaming
The MPU9250 9-axis Digital Motion Processor comes in the 24 Lead QFN package. The following figure shows the 2d model of the MPU9250 9-axis Digital Motion Processor. It shows us the physical dimensions of the components required when a PCB card is designed.
The datasheet link is given below to see further details and specifications of the MPU9250 9-axis Digital Motion Processor.