Getting a PI Zero two working with wireless USB

Support Product Questions
1

Hello everyone, hoping to get this in front of you help fill in the gaps.

I recently bought a Pi Zero 2 W, along with a Micro USB OTG Host cable (SKU: CE04761 in the store, here).

I’ve been using it alongside a Rii Mini X1 Wireless keyboard - the manual for which can be found here:

And the product page for which can be found here:

The USB dongle for the X1 works without issue via the OTG cable, but when I switched to a shim (to eliminate the cable from a build and save space), I haven’t had any response from the Pi.

That shim can be found at: USB to microUSB OTG Converter Shim | Buy in Australia | ADP006 | Pimoroni | Core Electronics

Here’s where it gets a little weird - I then tried the shim on a usb dongle for a Logitech MX Master 3 (found here: MX Master 3s Wireless Mouse - 8K Optical Sensor | Logitech) - which immediately worked.

With that in mind, I originally thought perhaps the issue was with the shim… but considering it worked with the Logitech dongle, that leads me to think the Rii X1 dongle is the issue.

Would anyone happen to have run into something like this? Better yet, if anyone can recommend a small adaptor that would work with the Rii X1, I’ll be extremely grateful - the Host cable’s just too big for the size of the project I’m working on.

Gut feeling is the shim doesn’t have the grounded pin that activates the ‘Host’ functionality of the port, and the Logitech dongle just flat out doesn’t need it, thus working without issue… but I’m hoping to ask here before I just go and buy a scattershot set of adaptors and go in blind.

Thanks for being patient with me, and if there’s any issues with the post or content please let me know and I’ll tidy up.

2

Hey @Thomas83807,

This is quite bizarre! I have investigated the shim, and the host pin does seem to be present. I cannot confirm if it is actually connected to ground, however, as the pins were basically inaccessible with a meter.

It may be possible to break out the connector to some jumpers to test, but I don’t think the pin would be included on the shim without providing its actual function.

That being said, I would assume the Logitech dongle doesn’t need the host pin to function, which would lead to your conclusion about the missing pin. Puzzling…

Do you have any other devices that you know require the host pin? That could be a great way to test the shim.

3

Zach, thanks for taking the time to look into this. It’s been living rent-free in my head as it’s the last thing between me and finishing up a project.

On your question regarding other devices that require a host pin - my understanding is that thumb drives require them to trigger the host functionality on the PI so it can power/interact with them, so I snagged a generic Verbatim 32GB Thumb drive which has a few files on it.

Tried it on my PC, picked up fine, tried it with the Pi using the OTG cable, picked it up fine (got the ‘removable device’ prompt)

Then immediately yanked the drive and cable, threw the shim in the drive, and put the drive into the port - and also got the ‘removable device’ prompt.

I also did the same with my main keyboard - a Topre R2A (found here: Product : REALFORCE A / R2A-US5-BK | REALFORCE | Premium Keyboard, PBT, Capacitive Key Switch) which worked with both the shim an the OTG cable; thought that might’ve fallen into the ‘peripherals’ group most posts/articles mention that require a host pin when thrown at an OTG port.

So either the Thumb Drive and R2A keyboard are an exception to the ‘generally needs a host pin’ rule, or the X1 keyboard dongle is a dud.

But the X1 keyboard dongle working with the OTG Cable is where that seems to fall apart…

I also went and snagged a generic Jaycar connector (Jaycar SKU: WC7725) and that works with the X1 keyboard dongle as well, so I’ve got two positive tests with the X1.

Last but not least, threw the X1 keyboard dongle in a Pi 3b+ running the same SD card formatted with RPI OS Lite that I pulled from the Zero… thinking perhaps bluetooth configuration was the problem, but confirmed the keyboard working as intended there too.

So I’m torn on pointing the finger at the shim - as so far at least one device that supposedly needs a host pin is working… but I also struggle to point the finger at the X1 keyboard as it works with the OTG Cable.

Does it seem like I might have missed the mark with my testing?

4

Hey Thomas,

I wouldn’t say you have “missed the mark” with your testing. A good way to figure out these things is to identify common factors, which is exactly what you’re doing.

I do think perhaps assumptions are being made which cannot be used as absolute. E.g. The thumb drive using OTG. It very well could, but as far as I’m aware, it definitely isn’t guaranteed. It could, or it couldn’t, depending on the functionality of the drive itself.

I would think the most concrete OTG device to use for testing would be a phone or a tablet. If it shows up as a removable drive accessible by your PC, you can be confident that the OTG pin is present and working properly.