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Topic: No i2c data to adafruit motor shield V2 on UDOO (Due) (Read 714 times) previous topic - next topic

I have an Adafruit Motor shield v2 which was altered per adafruit for 3v logic so as to be compatible with the Due on the UDOO.
I downloaded their Motor Shield V2 arduino library, built and uploaded the DCMotorTest sketch from an external PC using ver 1.5.6-r2 of the ide with the UDOO modified Bossac. (I've also used the UDOO iMX6 Debian with arduino IDE with the same results below)

The adafruit DCMotorTest sketch writes "tick", "tock" and "tech" to the serial monitor port with 5 sec, 5 sec and 1 sec intervals after them. I'm seeing 30 sec intervals after "tick" and "tock while after "tech" is the expected 1 sec. The DC motor on M1 is suspose to speed up and down and reverse direction, but it only runs at a constant rate and its output pulse modulation is unchanged.

The sketch controls the DC Motor via the i2c, however putting a scope on the SDA and SCL pins showed no data with both pins static at 0v DC.    A Due clear and Reset (via pins) brings both pins up to 3.3v.    I get the same results (no i2c data) with the Motor shield removed.

It appears that the i2c is not working. What is the best way to test it?   Preferablly by using my scope as I have no other components to interface to it.

Posts: 17
Joined: Sun Feb 23, 2014 9:23 am


There is an I2C scanner here.


If this works with the Motor Shield connected then you know IC2 is OK.


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