Raspberry Pi Detects I2C Device Sometimes

Question

I have my MPU-92/65 connected to my Raspberry Pi and it's sometimes detected but not always.

$ i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- 68 -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --  

Sometimes the 68 is there and sometimes it isn't.

The component is on a breadboard with the following connections:

• VCC to 5V
• GND to GND
• SCL to SCL
• SDA to SDA
• ADD to 3.3V

Why does it do this? How can I make it more consistent?

I remember getting it to work properly before.

Answer 1

The only reason for an intermittent connection is a loose connection. I suggest you check that each wire is securely soldered in place.

It is safer to power from 3V3 rather than 5V if the module will work at 3V3.

Answer 2

A lot of stuff about MPU 9250 in https://learn.sparkfun.com/tutorials/mpu-9250-hookup-guide (i2c, pull up, datasheet, ...).

For the power and the address selection :

VDD         Power supply        +2.4V to +3.6V
AD0/SDO     Address selection   I2C Slave Address LSB (AD0):
                                    Low: 0b1101000 ➫ 0x68
                                    High: 0b1101001 ➫ 0x69

So VCC to 3.3V is better and AD0 to GND to get address 0x68.