#pga2350 — Public Fediverse posts

A simple breakout for the Pimoroni #PGA2350 module.

https://diyelectromusic.com/2026/05/04/pga2350-breakout-pcb-design/

#RP2350 #PGA2350

PGA2350 Breakout PCB Build Guide

Here are the build notes for my PGA2350 Breakout PCB Design.

Warning! I strongly recommend using old or second hand equipment for your experiments.  I am not responsible for any damage to expensive instruments!

If you are new to electronics and microcontrollers, see the Getting Started pages.

Bill of Materials

• PGA2350 Breakout PCB (GitHub link below).
• Pimoroni PGA2350.
• SMT micro USB socket (see photos and PCB for footprint).
• 2x 2-pin tactile button switches.
• Double row, round pin header sockets.
• Double row, extended round pin header pins.
• Pin header pins or sockets as required for the breakout.

Reminder: This board is NOT compatible with the similar form-factor Waveshare Core 2350B.

Build Steps

Taking a typical “low to high” soldering approach, this is the suggested order of assembly:

• The micro USB socket.
• The PGA2350 round header pin sockets.
• Switches.
• Pin headers.

I’ve chosen to use pins for the breakout, but pin header sockets would be fine too.

Whilst it makes sense to fit the USB socket first anyway, it is also the most tricky part of the PCB, so if that gets messed up there isn’t much point in carrying on!

And it was really tricky for me. I’ve soldered them for power before, but this time I needed the data lines connected too. Going slowly, using lots of flux and a magnifying glass seemed to do the trick. I soldered a single case pin connection to hold everything in place whilst attempting the main connections, then tested everything for continuity and lack of shorts before moving on.

When cutting pin header sockets for the PGA2350 socket, they may need filing down on the ends slightly to fit snugly with no bending or forcing when arranged in the square.

Unfortunately the footprint for the buttons didn’t quite match the buttons I had. The holes are slightly too small. I opted to file down the legs of the buttons slightly and then apply a bit more force to get them in place. They went in well enough for me in the end.

Soldering pins to the PGA2350 itself was quite a hairy moment too. The labels look really cool, but they are not silkscreen, they are gaps in the mask I think. Regardless, solder will stick to them if not careful…

Here are some build photos.

Testing

I recommend performing the general tests described here: PCBs coupled with a thorough visual inspection.

As already mentioned, the USB socket should be checked for continuity and shorts before soldering anything else in place.

When confident everything seems ok, then the board can be connected by USB to a PC and it power up in BOOT mode and the standard RP2350 boot drive should be visible.

PCB Errata

There are the following issues with this PCB:

•  As already mentioned the footprints for the buttons have holes that are too small.

Find it on GitHub here.

Closing Thoughts

The button issue was an annoyance but ok. But I really need to find a better micro USB footprint to use as that was really quite tricky to get right.

The PGA2350, once it has all its pins soldered in place, requires a fair bit of force to fit into the socket, but it isn’t too bad. Getting it back out however isn’t so easy. It can be done with some gentle leverage in the corners, taking care not to bend any pins either on the PGA2350 itself or the breadout board.

But once all assembled and up and running, it seems to work pretty well.

Kevin

PGA2350 Breakout PCB Design

I’m wanting to do some experimenting with the Pimoroni PGA2350 which is a really neat, 25x25mm, RP2350 board with all 48 GPIO pins of the larger RP2350B bought out to two rows arranged in a square. But it isn’t very breadboard friendly.

More recently there are now DIP based breakouts that also support the RP2350B and all 48 GPIO, but eventually I’d like to use a RP2350B in a design of my own and the PGA2350 is such a good form factor to use for that. I’m not ready to attempt a SMD design using a bare RP2350 itself just yet.

So I had a need to be able to experiment with a PGA2350 and hence decided to create this simple breakout board.

Warning: There is a Waveshare RP2350 module (the Waveshare Core 2350B) in the same form factor, but this MUST NOT BE USED. The pinouts are slightly different but most significantly, some of the power and GND overlap with GPIO on the Pimoroni board. I might re-spin a version of this board for the Waveshare at some point…

Warning! I strongly recommend using old or second hand equipment for your experiments.  I am not responsible for any damage to expensive instruments!

If you are new to electronics and microcontrollers, see the Getting Started pages.

The Circuit

There is little more than the PGA2350 and some headers. There just a USB socket for communications and power, and buttons for BOOT and RESET.

I had to create my own KiCAD symbol for the PGA2350 however, but it is very similar to the symbol for the RP2350 itself.

I’ve also included some additional headers for GND, 3V3 and 5V (hanging off VBUS).

PCB Design

I’ve used the micro-USB socket footprint I’ve used in the past. I did think about using a micro-USB breakout board to make soldering easier, but wanted it to look a bit neater than that.

I also had to create a PGA2350 footprint to go with my symbol, but that wasn’t too difficult. Essentially setting the grid size to 2.54mm and keep adding pins. Numbering them took a while as I wanted the pin numbers to match the GPIO numbers as far as possible. There was probably an easier way to do this in KiCAD, but I often just work within what I know.

Then I added silkscreen GPIO numbers to all the breakout pin headers to make it easier to use.

I choose simple button footprints that I thought would match the two-pin buttons I have (spoiler: they didn’t. I had to bodge something together, but I’ll come to that when I write up the build guide).

Closing Thoughts

Pimoroni were selling pins and sockets in the PGA format, but they are now end-of-life. I’ve also found some 10×10, 68-pin PGA sockets (there are four additional pins, one on each inside corner) which I did wonder about using, but in the end I opted for a simpler footprint and will use dual-row, round pin, pin header sockets to mount the PGA2350.

I’m pretty sure that will work out ok.

Kevin