Technical Feature information of Audio Mezzanine board

mezzanine

#1

I have following few questions as I am planning to buy audio mezzanine board :

  1. Is the audio mezzanine board : https://www.96boards.org/product/audio-mezzanine/ compatible with Hikey 620 : https://www.96boards.org/product/hikey/ ?
  2. Do the 40 pin low expansion header on Mezzanine have the same mapping as the base otherboard on which it is used?
  3. What are the compatible cables for the 6 white ports for UART/I2Cs/etc.? I see they are a different kind of connector I have never seen before and its not clear from the picture. Can someone please share the cable links for reference or can jumpers be used on them?
  4. Hikey 620 exposes UART 3 as the default port for debugging. Is the same port exposed through mezzanine board ? (I know this one was stupid question, but lets confirm :slight_smile: )
  5. I see that there is a switch to have 3.3V and 5V voltage levels. Does that mean toggling the switch will provide equivalent level signals on the I2C0, I2C1 and UART pins?
  6. The spec says that mezzanine has 1 UART, 2 I2C and 3 GPIO connectors. How about the SPI pins 10,12,14 of Hikey 620 (https://github.com/96boards/documentation/blob/master/consumer/hikey/hikey620/hardware-docs/HiKey_Hardware_User_Manual_Rev0.2.pdf). Are they accessible in some way from mezzanine board? (since it completely covers the motherboard low expansion header, soldering could be an option)

#2

I have following few questions as I am planning to buy audio mezzanine board :

  1. Is the audio mezzanine board : https://www.96boards.org/product/audio-mezzanine/ compatible with Hikey 620 : https://www.96boards.org/product/hikey/ ?

With the exception of the audio features (that require the Dragonboard
specific analog header), yes.

Additionally it may be necessary to desolder the analog header on the
underside of the board. Some 96Boards have a large inductor here.

  1. Do the 40 pin low expansion header on Mezzanine have the same mapping as the base otherboard on which it is used?

Same pin out but not all the pins are implemented. See schematic for
detail.

  1. What are the compatible cables for the 6 white ports for UART/IOs/etc.? I see they are a different kind of connector I have never seen before and its not clear from the picture. Can someone please share the cable links for reference or can jumpers be used on them?

Search for “grove connectors”

  1. Hikey 620 exposes UART 3 as the default port for debugging. Is the same port exposed through mezzanine board ? (I know this one was stupid question, but lets confirm :slight_smile: )

The FDTI on the audio-mezz is connected to LS-UART1 on the low speed
connector.

  1. I see that there is a switch to have 3.3V and 5V voltage levels. Does that mean toggling the switch will provide equivalent level signals on the I2C0, I2C1 and UART pins?

Yes.


#3

Thanks @danielt for detailed answers.

One last clarification regarding #4 . Hikey 620 has only

  1. UART2_TX (pin#5) and UART2_RX (pin#7)
  2. UART3_TX (pin#11) and UART3_RX (pin#13)
    on Low Speed Expansion Connector.

And as I cross-checked, you perhaps mentioned in relation to Dragonboard 410, which has UART1_TX and UART1_RX on the same pins #11 and #13.

At same location on Hikey 620, we have UART3_RX and UART3_TX.

Hence, shall I assume the groove connector output UART0 (white coloured) on Mezzanine, just interfaces to pins #11 and pins #13 on the base motherboard?

(I am planning to use it with Hikey 620, not dragonboard)


#4

Thanks @danielt for detailed answers.

One last clarification regarding #4 . Hikey 620 has only

  1. UART2_TX (pin#5) and UART2_RX (pin#7)
  2. UART3_TX (pin#11) and UART3_RX (pin#13)
    on Low Speed Expansion Connector.

And as I cross-checked, you perhaps mentioned in relation to Dragonboard 410, which has UART1_TX and UART1_RX on the same pins #11 and #13.

Nothing to do with the Dragonboard.

LS-UART1 is the name of the pins on the connector itself
(https://www.96boards.org/pinout/ ). LS-UART1 is always pins
#11 and #13 of the low speed connector on every 96Boards product.

Without the LS prefix (low-speed) the UART number usually describes the
signal name to the SoC rather than the signal name to the LS connector.

At same location on Hikey 620, we have UART3_RX and UART3_TX.

As you have seen, the manuals for each board help you map SoC signal
names to pinout signal names.

Hence, shall I assume the groove connector output UART0 (white coloured) on Mezzanine, just interfaces to pins #11 and pins #13 on the base motherboard?

No.

LS-UART1 is connected to the built-in FTDI interface (micro-USB next to
the LS connector).

The UART0 grove socket is connected to LS-UART0 [hence the number ;-)].


#5

Oh. I got the point.

Also, i forgot earlier, do we need to provide any external power source to this audio mezzanine board or does it take it from low expansion header?


#6

Most of the board is powered from the base board. Only exception I am aware of is the FDTI circuit which is powered via it’s own USB connection (this is to avoid the UART disconnecting if you remove power from the base board).


#7

Thanks to provide all the clarifications. I have order an Audio Mezzanine. Hope it arrives fast.