SparkFun Forums

[paynterf]

Hi,

Just got a MPU-9250 imu, and am planning to connect it to an Arduino Uno I2C with several other I2C devices, all running at 5V. If at all possible, I don't want have to level shift the I2C lines to the MPU-9250; will connecting it to 5V I2C lines damage the unit? If it will, can you point me to any documentation/circuits for I2C level shifting?

TIA,

Frank

[paulvha]

Maybe this article will help you: https://playground.arduino.cc/Main/I2CB ... velShifter. According to the datasheet the MAX VDD/VDDIO is 3.6V I expect you will damage the MPU-950 if you connect 5V to the I2C lines. In the article they demonstrate how to use pull-resistors to 3V3 on SDL/SDA. It will mean that all the I2C devices need to be able to detect a "high" on 3V3, which is working on the edge of the specifications.. (but I have seen that work perfectly).

[jremington]

will connecting it to 5V I2C lines damage the unit?

Yes, unless you are extremely careful. The best approach is to not take chances, and use a level shifter.

Or, buy an IMU that is intended for 5V operation. Pololu sells several that work quite a bit better than the outdated MPU-9250. Some are even on sale: https://www.pololu.com/product/2469

For those, I recommend using the excellent, open source AHRS software RTIMUlib. See https://forum.pololu.com/t/state-of-the ... or-25/8091

[paynterf]

Thanks for the quick and informative replies. I implemented the 2 MOSFET bidirectional level-shifter circuit described in AN97055 https://cdn-shop.adafruit.com/datasheets/an97055.pdf, and am currently troubleshooting it. I also ordered one of the Pololu IMU's you linked to.

Regards,

Frank