mems

MEMS Integration

Integrating the MPU-9250 with the Arduino Uno Rev 3 via the I2C protocol

Documents

• MPU-9250 Register Map
  • Use the register map to determine what address to start reading bytes from the IC
  • We care about the accelerometer / gyroscope and that block of data starts at 0x3B

I2C

• Being done through the Wire.h library built into Arduino IDE

Circuit Diagram

      10 uF Capacitor
┌───────────┬───────┐
│┌──────────┴──────┐│
││ ╔══════════╗    ││ ╔═════════╗
││ ║ Arduino  ║    ││ ║ MPU9250 ║
││ ║ Uno  SCL >──┐ │└─< VCC     ║
││ ║      SDA >─┐│ └──< GND     ║
││ ║          ║ │└────< SCL     ║
│└─< GND      ║ └─────< SDA     ║
└──< 3.3V     ║       ║         ║
   ╚══════════╝       ╚═════════╝

Picture of wiring

• The AD0 pin is wired with a resistor to ground
  • Therefore the pin is still set to LOW rather than HIGH
  • This is not necessary but then pin was originally wired to be HIGH but then moved the resistor to groundbecause the default address is fine