Documentation of the Dragon Board

we want to use the Dragon Board and have one
but up to now i have not got a good documentation.
I have following documents:

The High speed expansion connector
should be 61082-061409LF on the board.

What is the type of the connector which can be connected ?

On page 18 in HardwareManual_DragonBoard.pdf is written:
6 High speed expansion connector
32 I2C2_SCL
34 I2C2_SCL
36 I2C3_SDA
38 I2C3_SDA

Is this one interface or are this two interfaces ?

What are the levels of the signals ?

Please send us missing information.

I think you are looking in the wrong document!

Part of the point of 96Boards is that they have a standardized layout. Thus a mezzanine board with a HS connector should normally designed for 96Boards CE compatibility rather than designed exclusively for Dragonboard 410C. This means hunting through board-specific documentation won’t work, you need to look at the specs (although if you want to exploit the 410C’s analog connector you will need to coordinate with information in the board specific docs).

Anyhow I believe all your questions are answered by the 96Boards CE specification. See (respectively):

  • Page 12: Expansion Board Connectors
  • Page 20: 60 Pin High Speed Expansion Connector (@sdrobertw: it looks like there is a typo in the DB410C hardware manual)
  • Page 12: High Speed Expansion Connector

Thank you for your answer.
I did not known that the Dragon Board was developed
after a 96Boards CE specification.
I have found the specification.
The questions regarding the I2C interfaces are answered.

But i do not understand that for the low speed interface mezzanine board
connectors those with 2.5 mm mated height are proposed.
The display connector has a high about 6 mm and the USB connectorabout 7 mm.
So a board to board distance of 8 mm is neccessary.
So far I have found one connector pair only for an add on board
which mates with the low and high speed connector,
high speed connector 61083-06440xLF from Amphenol FCI
and low speed connector MTMM-120-07-F-D-060 from Samtec.

The original spec recommends mezzanine board to board separation of 7 or 8mm. I believe of the LS connectors part numbers found in the spec in a 7mm board to board separation.

However, as you say, for a mezzanine that covers the whole footprint of the base board then 8mm is a better design in order to be comfortably clear of the USB connectors. That can make it tricky to identify suitable part numbers (though getting ones with extra long pins is one option).