CM4 - USB pinheader
Koen (10031) 8 posts |
The compute module IO board features a pinheader for 2 extra USB ports. If there isn’t, this would be a piece on my wish list. It would give the IO board a USB for the mouse, one for the keyboard and 2 more for a memory stick and maybe an external cd drive. |
Rick Murray (539) 13806 posts |
Looking at the datasheet, it’s just two of the four ports supported by the onboard USB hub. Two are provided on the board, and the other two can be added later. Note, however, that I would imagine that all of this eventually goes through the single physical USB port on the Pi itself, so while you can add all sorts of new things, it is no different than daisy chaining external hubs. More connectivity, but everything will be sharing the same bus and the same bandwidth. |
Chris Hall (132) 3554 posts |
No software is required, just connect to the header. |
Chris Gransden (337) 1202 posts |
Just plug it in. I had to bend out one of the pins. The one nearest the edge of the board. All the adapters I had are 9 pin. |
Rob Andrews (112) 164 posts |
Don’t bend the pin put a hole in the plastic header block |
Chris Hall (132) 3554 posts |
I added a 6-pin header plug with eextended pins, then cut off the sixth pin and bent the fifth pin outwards and soldered a micro USB breakout board to that. This lifted it nicely above the Ethernet socket and I used a flexible micro B to USB A cable to connect to a 4-port USB hub. You can just see it here |
Koen (10031) 8 posts |
Ok, thanks for the advice. There is also this 4 pin cable header: https://www.alternate.be/p/o/r/DeLOCK_USB_Pin_header_female___USB_A_2_0_female_adapter@@rduccf.jpg |
Rick Murray (539) 13806 posts |
I’m not sure it’s a good idea to try plugging in random cables…
The CM4 I/O board datasheet (a quick Google will find it) contains the schematics. It’s all there, you just need to know how to read it. For you, I’ve clipped out the relevant bit: |
Koen (10031) 8 posts |
Many thanks, these schematics make it much more clearer. |
Rick Murray (539) 13806 posts |
Usually, because the pin marked with a square is by the text “Exte”(rnal USB). However to be certain I’d whip out a multimeter and do a continuity test between the two that ought to be Gnd and anything that should also be, like one of the socket shields. |