Hi there!

So I got a request to study USB+ WiFi being used in the same port.
Generally the idea is that in default condition, the port (Lets say Port Negative (PN) and Port Positive (PP) will be used for USB2.0 function.
Only sometimes, user will want to plug in WiFi module to switch it to WiFi function



Hopefully this pic helps.

My question would be basically ; is this a good idea? I can already estimate that trying to match the skew is going to be a pain. And my gut feeling is telling me this is going to be painful.

*I did try to search online, but having found nothing, either this IS a bad idea and no one ever done it, or I'm just getting my keywords wrong.

Any thoughts would be appreciated!

 

Welcome to AAC.

Could you describe the application? There are a lot of details that will be automatically implied by that and we'll have a much better chance of provide useful answers.

 

Hi there!

So I got a request to study USB+ WiFi being used in the same port.
Generally the idea is that in default condition, the port (Lets say Port Negative (PN) and Port Positive (PP) will be used for USB2.0 function.
Only sometimes, user will want to plug in WiFi module to switch it to WiFi function

View attachment 303032

Hopefully this pic helps.

My question would be basically ; is this a good idea? I can already estimate that trying to match the skew is going to be a pain. And my gut feeling is telling me this is going to be painful.

*I did try to search online, but having found nothing, either this IS a bad idea and no one ever done it, or I'm just getting my keywords wrong.

Any thoughts would be appreciated!

On one connector?
The usb is known, but what signals do younwant to send to the wifi you show ?
What does the person that's given you this expect of you ?
Is this commercial, or a home work or university project ?

 

Trying to fill in some blanks....

"into one port" – does this mean into a UART on the microcontroller (since you've labeled it Tx/Rx)?

Does the wifi "piece" (module, custom circuit, whatever) output serial?

Will both USB and wifi I/O be in use at the same time? Does either have priority over the other?


You can't just tie Tx lines together since they idle at a fixed high or low (don't recall which), so the inactive input would fight with the active. If only one input will be used at a time, a logic gate will sort the the signals out (the required gate type depends on whether the Tx output idles high or low; essentially, you need to achieve an OR function).

If both inputs could be active at the same time, either from the same or different sources, the situation is much more complicated. You have to give one of the inputs priority and block the other. If the sources are different, then you have to figure out how to detect/deal with missed transmissions.

 

There are likely USB devices that implement WIFI. Perhaps that is what they were talking about. You simply plug the WIFI adapter into your USB port and now you have WIFI connectivity (with the appropriate software.)