Here is an update to the HDMIUSB board

SCH_Schematic1_2026-06-13.pdf

 




This is configured using OPTION RESET PICO COMPUTER 3 with the 6.03.00 firmware (RC18 onwards. This configuration applies to every RP2350 build. In the case of VGA builds you can use a little PCB adapter to connect to the I/O port.



In the case of the WEB and bluetooth builds it uses the official Raspberry Pi RM2 (RMC20452T) wireless module which effectively makes the board a super RP2350B Pico2-W

I've been using a first prototype to test the new HDMIWEB build and all looks good. Note that I've simplified the DVDD supply by using a fixed 1.3V regulator which works perfectly up-to 396MHz and the board now includes a 4 Pin JST-SH Cable (Qwiic, STEMMA QT, Qw/ST) connector to allow modules to be chained off it if required. I've also replaced the p-channel mosfet which switched the USB host 5V rails with a proper higher power but current limiting switch.

As before the board provides I2S audio has a DS3231 RTC and all the usual goodies. I'm waiting on a second prototype that has a trivial pin usage change and assuming all good will then release the gerbers. Cost for a board fully populated other then the RM2 module (JLC/LCSC don't yet stock it, but they did do the PCB layout for me) is about USD45 each in 5-off quantity
Edited 2026-06-13 21:40 by matherp

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  matherp said  

makes the board a super RP2350B Pico2-W

With PSRam. Super indeed. How solderable is the Wifi module? Any suggestion from JLC that they will stock it?

If any in Canada want some, I would be interested in placing an order and selling 3. Or buying 2 from someone who places an order.

Beautiful. I want two of them.

The RM2 is solderable by hand. The pads extend a bit beyond the outline of the device and it has solder pad cutouts like the Pico. However, the easy way is a bit of solder paste and a heatgun - all done in 10 seconds

That looks lovely.  How's the USB hub work? I will take a look at how you do the 1v1 rail because I hate their precious inductor, and having adjustable voltage really has little value unless you care about power consumption.

  jvanderberg said  

That looks lovely.  How's the USB hub work? I will take a look at how you do the 1v1 rail because I hate their precious inductor, and having adjustable voltage really has little value unless you care about power consumption.

hi Josh,
   right above the first image in the top posting from Peter is a link for downloading a PDF of the schematic. it uses a TLV70313DBVR which is a 300mA LDO linear regulator providing a 1.3v output. this feeds directly to DVdd on the RP2350.


cheers,
rob   :-)
Edited 2026-06-14 14:31 by robert.rozee

Yep, I saw the schematic, thus 'I will have to take a look.'  Thanks.

He's at it again, folks!        

Looks good.

I like the idea of native HDMI, but you can have VGA via the wee external adapter board if  you want.  That covers all the bases very nicely, I think!  

Of course, you could probably make an adapter to fit the HDMI output to give vga via a suitably tweaked resistor network. You have 8 GPIO pins you can toggle when the HSTX isn't being used. You can subtract 220R from each VGA resistor.

That is an excellent idea Mick.
And two more GPIO as a bonus!

You mean like this

SCH_Schematic1_2026-06-14.pdf

Nice...
Or an option to use the other GPIO pins to get RGB222 (memory allowing). ;)

It is possible to make a palette switch for the VGA video output adapter

By the way, the VGA adapter doesn't necessarily have to be external. You can create a series of HSTX pins on the board and connect the VGA adapter board to them when needed.
Moreover, you don't even have to disconnect it; experience has shown that the connected VGA resistor matrix doesn't affect the HDMI video output.
Edited 2026-06-14 21:58 by javavi

Javavi,

Note there is already 220 ohm on the HDMI main board.
You have to adapt resistor values, which rules these jumperable options out (outputting pure blue will feed back into R and G).

Volhout
Edited 2026-06-15 00:43 by Volhout

You can't "create" HSTX pins anywhere, they are fixed in hardware and are non-defineable. You can, with some risk, parallel them to other pins but it's not recommended due to the very high frequencies involved. You might get away with it, you might not. There's no need to do it anyway. We have a standard connection for VGA on the PicoMite, adding alternatives introduces software compatibility issues with PicoMite software which are best avoided.

As we are designing a socket adapter, not a VGA output, the 220R series resistors are fixed and there is no direct access to the HSTX pins.

The boards are in and everything works perfectly



Gerbers, schematic and design files

Pico Computer 3 2026-06-25.zip

Cost for 5 boards fully built is just under USD180 + any applicable tax and shipping. You can save money by soldering headers etc. yourself. I bought them without headers, flash, RTC, PSRAM and UART chips and cannibalised old boards for these, that brought the price under USD100. JLC don't stock the wireless module but it is available from Pimoroni amongst other places. Of course, it isn't needed for the board to work with one of the non-Web firmware builds. It can run any of the RP2350 firmware builds and you can use OPTION RESET PICO COMPUTER 3 to configure it.

I have 3 spares available for GBP40 for anyone in the UK who wants one - PM me if interested. GBP44 if you want the wireless module included.
Edited 2026-06-26 04:03 by matherp

The HDMI/VGA adapters have arrived from JLC. I just got the board made up by JLC with the SMD resistors - with a discount token this cost me USD8 including tax and shipping!. I then bought the Male HDMI connector from LCSC. This mounts to both sides of the PCB but is really easy to solder as the pin spacing is effectively twice that of a normal HDMI connector (flat side up), the VGA connector and headers I already had in stock. This means I can test or use every RP2350 build with the same main Pico Computer 3 PCB and this adapter    OPTION RESET PICO COMPUTER 3, OPTION VGA PINS GP12, GP14

Schematic, design file, gerbers etc
HDMI USB Adapter_2026-06-26.zip

I will love to buy one if this board arrives to the US or Canada  

  LeoNicolas said  

I will love to buy one if this board arrives to the US or Canada

If one more person in Canada wants one or two, I'll order them--full installation of parts by JCLPCB (except for the wifi if not available).

Hi Lizby, I'm in for one, as if the several designs I have already are not enough!
PM me when you have a price and need payment. Also if you a spare MB for Mixtel's RPZ module and other addons let me know and you can include that as well.