Need advice PicoMiteHDMI PS/2 PCB layout

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Amnesie
Guru

Joined: 30/06/2020
Location: Germany
Posts: 746
Posted: 09:50pm 02 Jul 2025      

  matherp said  
If there isn't I would prefer that you don't imply there is and not state in open forum

... when many others do not see an issue.


Peter,

others DO SEE an issue, again; I am NOT the only one. I've tried all sort of things,
here are two (short videos with the problem with two different keyboards:

Keyboard 1

Here the letter "s" is missing

keyboard 2

Here the letter "t" is missing

Is that typing really fast? I don't think so, problems start really quick if I increase speed.

Further explanation:

-Voltage is spot on 5V (measured)
- the micro usb to USB OTG adaptor is working fine
- even IF there could be a problem, I tried to solder wires directly to the TP2, TP3 etc. under the Pico board! Same result.
- I tested not only one device (Pico) but four different
- I tested five different keyboards

But even if I have a very "rare" issue, why has the forum user "ebbandflow" encountered the SAME issue? Strange! Coincidence? I don't think so.


  ebbandflow said  
"it appears the existing problem is that the RP2040 and RP2350 simply lack enough oomph to handle USB keyboard + mmbasic + video generation all at the same time.... I found the input speed is an issue even without a video display.  


  ebbandflow said  
Hi Daniel, I struggled with the same issue and ended up having luck with ps2x2pico and an american keyboard layout and posted about in the last post here...


But most of all - again - I am dissapointend how you deal with criticism. This whole topic was about asking for help if anyone could see a problem with my pinout for my next PCB design, I just wrote that there is a major flaw with the USB, which is correct and proven. But the "best" thing is: I don't care at all about this, I have a solution for my case and I am fine with this. So please don't tell me I'm not allowed to express legitimate criticism when something obviously isn't working, and then justify it by saying that most people don't have problems. That's just not how it works. Whatever the case, I'm slowly getting tired of this kind of conversation. With all due respect for your work.


With your attitude, I don't feel like dealing with this any further. I have my solution, and that's fine.

- Daniel
Edited 2025-07-03 08:31 by Amnesie