I2C Scanner not detecting MPU-9150

Projects Networking, Protocols, and Devices
1

Hey all,

I'm trying to get my MPU-9150 to work with my Arduino UNO, but when I load up the I2C scanner, it doesn't detect any devices at all. I obtained the scanner from below:

http://playground.arduino.cc/Main/I2cScanner

I've connected it in the following fashion:

Arduino - MPU9150
3.3V - VCC
GND - GND
A4 - SDA
A5 - SCL
Digital2 - INT

I haven't soldered the connections, they're in my breadboard.

What could be causing the scanner to not detect any devices? Maybe the connections themselves aren't secure and I need to solder them, or maybe a faulty wire?

Any help would be appreciated :slight_smile:

2

Hi, try adding two pullup resistors. 4K7 between SDA and VCC and the same between SCL and VCC.

3

I_like_pizza:
Hey all,

I'm trying to get my MPU-9150 to work with my Arduino UNO, but when I load up the I2C scanner, it doesn't detect any devices at all. I obtained the scanner from below:

Arduino Playground - HomePage

I've connected it in the following fashion:

Arduino - MPU9150
3.3V - VCC
GND - GND
A4 - SDA
A5 - SCL
Digital2 - INT

I haven't soldered the connections, they're in my breadboard.

What could be causing the scanner to not detect any devices? Maybe the connections themselves aren't secure and I need to solder them, or maybe a faulty wire?

Any help would be appreciated :slight_smile:

is your Arduino powered by 5V or 3.3v?
If you are using a standard UNO, it is 5V.

Unless the MPU9150 has 5v tolerant I2C pins(IT Doesn't based on the MPU9150 Spec Sheet), you are going to damage/destroy the Sensor.

I2C needs pullup resistors (for the UNO 4.7k ohm between VCC(5v) and SCL AND SDA. so when the bus is idle 5V will be applied to the SCL and SDA pins of the Sensor.

An I2C level shifter(translator) is usually used, something like this from AdaFruit I2C level Shifter

to use this level shifter connect GND, 5V to HV, Arduino SCL - B1 Arduino SDA - B2, Sensor SCL -A1, Sensor SDA -A2, 3.3V to LV.

If your sensor is not 5V tolerant your could have destroyed it, or it just cannot function with 5V on SCL, SDA.

Second Though, Are you using a 'module' with built in level shifters/power supply? If this is the case then you might get away with adding the pullups. If it is not a 'module' with level shifter you need level shifters.

Chuck.

Check out my Kickstarter Project Memory Panes an expansion RAM Shield for Mega2560's. It adds 1MB of RAM for those projects where 8KB is not enough.

4

It is possible to use the Arduino Uno with the MPU-9150 module without level shifter.
If the MPU-9150 has a voltage regulator on the board, then apply the Arduino 5V to VCC.
The module from Sparkfun doesn't have it, and 5V will destroy the sensor :o

The voltage regulator is often a small black smd component with 5 pins.