# Confused about NoteCarrier XS schematics

**URL:** <https://discuss.blues.com/t/confused-about-notecarrier-xs-schematics/2207>\
**Category:** Hardware\
**Created:** [July 5, 2024, 10:22am UTC](https://discuss.blues.com/t/confused-about-notecarrier-xs-schematics/2207 "2024-07-05T10:22:06Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![bernd](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/bernd/32/787_2.png) [@bernd](https://discuss.blues.com/u/bernd)\
**Post date:** [July 5, 2024, 10:22am UTC](https://discuss.blues.com/t/confused-about-notecarrier-xs-schematics/2207/1 "2024-07-05T10:22:06Z")

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We are thinking to make a variant of our RAK13102 NoteCard Carrier that supports the StarNote.  
But I am confused when looking into the schematics for the NoteCarrier XS.  
On sheet two it says the NoteCard slot is using I2C to talk to the StarNote slot:

 ![image](https://us1.discourse-cdn.com/flex020/uploads/blues/original/2X/6/6cb04f0d2905e1a693f05017ccaa3b4223a006b3.png)

But when looking at the StarNote Connector on sheet 6, there is no I2C, only a serial connection.

 ![image](https://us1.discourse-cdn.com/flex020/uploads/blues/original/2X/6/61af38832682d236abed3d47cad6e51508df07eb.png)

What is the required connection between the NoteCard slot and the StarNote slot?

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**Author:** ![bsatrom](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/bsatrom/32/3_2.png) [@bsatrom](https://discuss.blues.com/u/bsatrom)\
**Post date:** [July 24, 2024, 11:31pm UTC](https://discuss.blues.com/t/confused-about-notecarrier-xs-schematics/2207/2 "2024-07-24T23:31:04Z")

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Hey @bernd that’s a typo on the Block diagram. comms between the Notecard and Starnote are serial only, so the schematic is correct.