why does I2C bus malfunction on arduino headers of FRDM K64F board

[binyang]

Hi there,

     I bought one FRDM K64F board from channel in 2015, but the I2C bus does not work on the arduino header. It cannot detect any I2C slave devices connected via arduino header. However, it can detect the FXOS8700CQ on that I2C bus (FXOS8700CQ is integrated into the FRDM board).

     I test another FRDM K64F board with the same test binary, this issue does not appear on that board. The difference between two boards is the version:

the one with issue: 700-28163 REV A / SCH-28163 REV C

the one without issue: 700-28163 REV C / SCH-28163 REV E

Could someone give a hint what is going wrong with my board? Thanks.

BTW, I do not have oscilloscope to capture the I2C signals.

[Jorge_Gonzalez]

Hello Bin Yang:

This must be caused by an errata in FRDM-K64F boards with schematic version previous to D1. The I2C lines were swapped in the old revisions of the board. Please have a look at the document:

http://cache.nxp.com/files/32bit/doc/errata/FRDMK64F_ERRATA.pdf

But as you noticed the issue was fixed with the latest board revisions.

We are sorry for the inconveniences.

Best regards,
Jorge Gonzalez

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[binyang]

Hi Jorge,

     Could you explain more about the errata: http://cache.nxp.com/files/32bit/doc/errata/FRDMK64F_ERRATA.pdf?

What is confusing me is that Table 2. (Correct signals FRDM-K64F Signal Arduino Uno R3 Signal) mentions that signal for J4-10/12 are I2C0_SDA/SCL, while I2C0_SDA/SCL are connected to PTE11/10 as well. However, from schematic and K64F Ref. Manual, we can see PTE11/10 can only be configured as I2C1_SDA/SCL, not I2C0_SDA/SCL...  So there must be something wrong.

BTW: the Arduino Uno schematic indicates that Pin AD4/5 are configurable as ADC or I2C signals, which are the same as SCL/SDA pins at J2-18/20 . Could you tell if the I2C bus on AD4/5 (J4-10/12) are distinct from the one on J2-18/20 ?  Thanks.

[Jorge_Gonzalez]

Hello Bin Yang:

Sorry for the delay to reply.

You are right, the Table 2 has wrong I2C number for J4 signals, it should be I2C1. Sorry for the confusion created, I will report this.

About Arduino headers, the pins J2-18/20 are connected to K64 pins I2C0-SDA/SCL while pins J4-10/12 are routed to K64 pins I2C1-SDA/SCL, so it is a different I2C bus, unless both pairs of pins are connected to the same bus in an Arduino shield for some reason.

I hope this helps to clarify.

Regards!

Jorge Gonzalez

[binyang]

Hi Jorge,

Now it is clear, thanks.

Best Regards,

Bin Yang, Alliances FAE, Wind River

Direct +86,10,84777126 Mobile +86,13811391682 Fax +86,10,64398189

Skype: yangbincs993

[binyang]

Hi Jorge,

Thanks for your information, I will take a careful look at that.

Best Regards,

Bin Yang, Alliances FAE, Wind River

Direct +86,10,84777126 Mobile +86,13811391682 Fax +86,10,64398189

Skype: yangbincs993