USB through High Speed Expansion connector


#1

Hi,
According to D410C Hardware Manual Port 3 of the USB HUB is routed to the High Speed Expansion connector.
Is someone knows how to use this USB port ?
Thanks,
Ronen


#2

Well, this is a standard USB line with D+ (HS pin 51) and D- (HS pin 53), so you can route these lines to a standard USB host port (e.g. USB type A female) or directly connect them to a USB device.


#3

I see. Thanks
It worked for me.
Another question - What shall be the name of the card / flat cable that should plugged into the HS Connector.
Can you point to a web address i can buy it from?
Thanks,
Ronen


#4

The part numbers of the connectors used on the boards are found in the 96Boards CE spec. IIRC the datasheet for this part helps you find the part numbers of partner connectors.


#5

Datasheet for the 61082 family to save you looking it up:


#6

One of the things that makes me very sad about the 96ce spec is that it specifies the 3.7mm receptacle height for the HS. That provides for a maximum board to board separation of only 8mm (given the 7.7mm plug). That doesn’t give enough clearance to use through hole components in the vicinity of the two usb-a sockets unless you clip the pins flush with the board, which really isn’t an option except for hand-made mezzanines. It would have been nice if the spec specified the 7.7mm receptacles, which would provide a 9-12 mm board separation range.

Anyone know of any sneaky tricks to get the boards out to 10+ mm?


#7

One of the things that makes me very sad about the 96ce spec is that it specifies the 3.7mm receptacle height for the HS. That provides for a maximum board to board separation of only 8mm (given the 7.7mm plug). That doesn’t give enough clearance to use through hole components in the vicinity of the two usb-a sockets unless you clip the pins flush with the board, which really isn’t an option except for hand-made mezzanines. It would have been nice if the spec specified the 7.7mm receptacles, which would provide a 9-12 mm board separation range.

Anyone know of any sneaky tricks to get the boards out to 10+ mm?

Not any particular clever ones for the board separation.

If you just need a bit of space for thru hole connectors on the edge of the
mezzanine you could overhang by 10mm on the LS side of the board. This
would still be reasonably strong mechanically. You’d need to be careful
of the power jack though (no components and a silk screen to help folks
with big barrel power leads saw off the corner?).

Whether this works really depends on what you are trying to connect can
whether its best as a front panel of back panel connector.


#8

Hi @doitright

As you have correctly pointed out, there are two different mating connectors in the spec, one that gives a 7mm board to board separation, and one that gives an 8mm board to board separation.

The 7mm connector clears the USB connectors with next to nothing to spare. If you look carefully at the spec for the USB connector (or at least the one we used) you will see that the body of the connector is just under 7mm tall, only the flange at the front edge of the connector rises to 7.7mm tall. The USB connectors are just slightly beyond the edge of the board so the flange doesn’t interfere with the mezzanine board, and there is some clearance to the USB connector body.

If you use the 8mm connector, then ‘technically’ you do have 1mm of clearance which is enough for most surface mount components in the area above the USB connectors.

The reality of the situation is a little worse, several things can go wrong:

  1. the mezzanine boards do flex and the components under the board (or the untrimmed leads) can make contact with the USB connectors,
  2. usually people are too lazy to install the standoffs between the boards so the boards don’t sit parallel.
  3. you can’t get off the shelf 2mm connectors for the low-speed connector that have 7 or 8mm board to board spacing, so the boards don’t sit parallel.

I would recommend a couple of things: Avoid putting components or through hole leads in the vicinity of the USB connectors, if you have to do this, put an insulating layer over them (such as Kapton tape or Fish paper) to prevent inadvertent contact with the USB connector body. The other thing we see a lot of is the mini-mezzanine boards that simple don’t extend over the connector zone.

One other challenge with the spec, technically the CE board manufacturer could put a heat sink above the component area, the heatsink can be 7mm tall (so far no-one has). If you use the 7mm board-to-board spacing then you can’t put any components (not even 0201 resistors) on the bottom side of the mezzanine board.

Since you can’t really use the bottom side of the mezzanine board it limits the amount of circuitry you can put on the board, you have a couple of options. 1) You can make the mezzanine board larger that the CE board, then you can have as much surface area as you want. or 2) you could divide your circuitry up into multiple boards and stack the boards. An example of this is the Audio Mezzanine Board which can be placed between the CE board and almost any mezzanine board. The D3 Engineering team showed me this trick while they were debugging their camera board, the stack allowed them to access the serial port through the Audio Mezzanine Board.

Hope this helps.

Full disclosure: I am currently unemployed and looking for work.


#9

The low speed connector is actually no trouble at all.
While not incredibly common, you can buy connectors of virtually any height for that.

Here are two options;
https://gct.co/board-to-board-connector/list?pitch=2.00mm&gender=Header&orientation=Straight&numberofrows=Dual&mounttype=Surface%20mount

The “single insulator” goes up to 15mm, the “double insulator” goes up to 28mm.
So its looking like the only option for just adding space would be to make a high-speed extension which would involve a plug, receptacle, and a small pcb. That would yield minimum ~10.5mm separation with half-mm pcb.

Problem there is that its not cheap.


#10

Hi,

At first place i thought my USB female connector routed to HS Exp worked but eventually i found it not working.
Anyhow i would be happy to understand where should i take the Vbus from (i’ have GND, D+ and D- from HS Exp but Vcc or Vbus is missing) , any idea?
Please note: my goal is to plug a custom board via the HS Exp connector and to have the D410 recognized it via USB.

Ronen


#11

You can find 5v on the ls connector.


#12

I just routed the Vbus directly from J2 (USB Port #2) and this time it really worked for me.

Anyhow I’ve wondered how come a 3rd USB port is available through the HS Exp. without Vbus?
The only option i can see is a bus-powered i.e. power comes from host, separate Vbus is not needed.
Anyone can confirm this?


#13

I think like @doitright already mentioned, you have to take Vbus from the +5V pin on the low speed connector.

If I connect a DSI panel to the high speed connector, I have to generate 3 or 4 different voltages to supply to the panel, that even depend on the panel being used, so I think the reasoning behind the HS connector is “no supply, signals only”

Also, the current rating per pin of the HS connector is only 0.8A. Enough for USB, but not giving lots of headroom if you want to crazy things on top of a 96boards.


#14

I have tried other solution similar to what has been suggested: I took the +5V from the LS Exp. and wired it to my Custom Board which eventually connected to the DB410c through USB Port #3 (via HS Exp.). So power comes from the other board.


#15

Below is a snapshot of my setup.


My final goal is connecting the two boards via the HS & LS connectors only.


#16

Hi Folks

The idea is that whatever is plugged into the HS port is responsible for providing appropriate circuitry to power the peripheral.

If the expansion board provides its own USB peripheral it is safe to hook this up to the 5V supply on the LS connector and to skip an ESD protection simply because we can know in advance what the current draw will be and that nothing should be sending static spikes down the D+/D- wires.

However if the expansion board simply exposes the D+/D- signals as an extra type A socket then it is best to add some protection circuitry (ESD protection, over-current, over-voltage).

In @Ronen’s case where the additional type A has been added as a board hack rather than on an expansion board then we can also take some short cuts (compared to a generic 96Boards hack). On this board then stealing power from the existing type A port is probably better than using the LS 5V output. Each type A on DB410C has an independent current limiter that triggers at ~1A so should still provide the required 500mA per socket). The new socket will also have slightly less ESD resilience than the other sockets. The hub used on the DB410C has some ESD protection but less well specified than the TPD4S214 used for the other sockets on this board. I’m afraid I have no idea if this matters or not :wink: .


#17

That board looks like it’s for a raspberry pi.

Make sure that you are aware that the rpi works at 3.3 volt I/o and the db410c works at 1.8 volt I/o. You can fry the db410c doing wiring like that if you aren’t absolutely sure that it’s only going to put out 1.8. If you’re not sure, you need a level shifter.

Also, presuming that you haven’t got it to work yet, you could have damaged the db410c already if you have even just applied power to that apparatus.

Could you identify what that board you are connecting to actually is?


#18

Hi everybody,

I dig up this topic because I need to meet the same requirements as other people in this thread for designing an expansion board.

As @danielt said, if the expansion board use the D+ and D- provided by the High Speed Connector simply for exposing an extra USB-A connector, I should add some protection circuits.

So, I implemented the same protection circuit used on the DGB410c (TPD4S214), everything is fitting good but there is only one thing that stuck my design. On the DGB410c, the enable pin of this circuit is driven by the signal called “USB_SW_SEL”, it allow the USB controller to activate or not each protection circuit.

This pin seems unexposed on any of connectors (I checked LSC and HSC, but both seems to not provide it).

Any solution for this issue ? Maybe I missed something.

Thanks for reading :slight_smile:.


#19

Hi @Will

You are correct, the signal is not exposed. You can simply hard wire it to always enabled. The only reason to not hardwire it is if you want to be able to turn the port on/off to save power. If you really need to turn it off, you can wire it to a GPIO. Ensure that you have the correct signal levels if you do wire to a GPIO.

Lawrence
Searching for a job…


#20

Hi @ljking,

Thanks you for validating my explanation, we are gonna set it enabled by default. My design already has levels shifters for signals communicating between IC’s at different supply voltage. Thanks for the advice :slight_smile:.