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Grogster

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Joined: 31/12/2012
Location: New Zealand
Posts: 10125

Posted: 11:11pm 14 Nov 2026

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Hi all.

Can someone - probably Peter - tell me if the BOTTOM USB socket on the G2 boards with the v7 FW, is supposed to work or not?

No matter what I try, NOTHING is EVER recognized on the BOTTOM USB socket, and I have now tried about SIX different boards, and NONE of them will recognize ANYTHING on the BOTTOM USB socket.

The top one sees everything fine, and if I plug in a USB hub to the TOP socket, I can have a keyboard, mouse and USB flash drive all plugged in and the CMM2 sees them all fine.

But NOTHING AT ALL on the bottom socket on ANY of the boards I have here.

I seems unlikely that six different boards could all have faulty bottom USB sockets, so can I get some clarification here?

Perhaps the new v7 FW only supports the TOP USB socket?
Perhaps that was mentioned somewhere else, but I missed it?

Smoke makes things work. When the smoke gets out, it stops!

matherp
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Location: United Kingdom
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Posted: 11:15pm 14 Nov 2026

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RTFM?

The bottom socket is for a PS2 mouse

Grogster

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Posts: 10125

Posted: 11:27pm 14 Nov 2026

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Oh, OK.

I thought the new FW did away with needing a PS/2 mouse, and they were both on the new USB stack, cos the new FW supports USB mice, so why would you NEED a PS/2 mouse - on a USB port anymore, when USB mice are now natively supported....

My assumption, but that's good to know - I will make sure it is mentioned in my little blurb thing I include with every unit.

If I wondered what was going on, I can guarantee others would too.

Smoke makes things work. When the smoke gets out, it stops!

matherp
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Location: United Kingdom
Posts: 12205

Posted: 08:37am 15 Nov 2026

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The G2 board does not have a usb hub so there is no way the firmware can connect anything usb on that connector. It was specifically designed to allow a PS2 compatible mouse to plug straight in and work and this is clearly documented.

I thought seriously about including an on-board hub on the G3 like the Pico Computer 3 but decided against it. The STM32H743 has a silicon limitation that only full-speed usb devices are supported through a hub.
This would mean that the vast majority of old keyboards and mice which are low-speed wouldn't work.
I therefore decided to leave the wiring as-is in the G3 and let the user connect via an external unpowered hub to the USB if they so desired. They will then have the restriction on full speed only devices and will need to select accordingly.
Plugging a low speed keyboard direct on the G3 will still work and coupled with a PS2 mouse and Wii Classic you have a complete gaming setup.

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