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fred777
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Joined: 01/07/2021
Location: United Kingdom
Posts: 106

Posted: 02:03pm 09 Oct 2026

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Hi all,
i have just received this nice little RP2350A board from China (alixexpress) called "Spotpear RP2350A-Linux-Pro Board" for 11GBP (so under 15USD).

First impressions are very positive, it has the "normal" Pico formactor but adds a SDCard slot and 8MB PSRAM.
Seems to run fine @384Mhz

> option list
PicoMite MMBasic RP2350A V7.0.00b6
OPTION FLASH SIZE 16777216
OPTION COLOURCODE ON
OPTION CASE UPPER
OPTION PICO OFF
OPTION CPUSPEED (KHz) 384000
OPTION DISPLAY 36, 100
OPTION SDCARD GP21, GP22, GP23, GP20
OPTION COMPILE ON
OPTION PSRAM PIN GP19

> list pins
GP0 1 OFF
GP1 2 OFF
GP2 4 OFF
GP3 5 OFF
GP4 6 OFF
GP5 7 OFF
GP6 9 OFF
GP7 10 OFF
GP8 11 OFF
GP9 12 OFF
GP10 14 OFF
GP11 15 OFF
GP12 16 OFF
GP13 17 OFF
GP14 19 OFF
GP15 20 OFF
GP16 21 OFF
GP17 22 OFF
GP18 24 OFF
GP19 25 Boot Reserved : PSRAM CS
GP20 26 Boot Reserved : SD MISO
GP21 27 Boot Reserved : SD CS
GP22 29 Boot Reserved : SD CLK
GP23 41 Boot Reserved : SD MOSI
GP24 42 OFF
GP25 43 HEARTBEAT
GP26 31 OFF
GP27 32 OFF
GP28 34 OFF
GP29 44 OFF

docs and schematics are here: docs

I have only tested the "basic" version of mmbasic, no hdmi/vga/usb testing done yet.
Will do some more testing but I really like this board so far.

Volhout

Guru

Joined: 05/03/2018
Location: Netherlands
Posts: 6169

Posted: 02:11pm 09 Oct 2026

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Cannot use HDMI. You need access to GP19 (HDMI connects to GP12...19).
And GP19 is used for PSRAM.

Volhout
Edited 2026-10-10 00:11 by Volhout

PicomiteVGA PETSCII ROBOTS

matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 11989

Posted: 02:14pm 09 Oct 2026

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Won't work for HDMI without removing the psram and won't work for VGA with standard pins so you can't plug it into the sc board for example. Otherwise really nice, perfect for a data-logger etc. Good find!

Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 9181

Posted: 03:55pm 09 Oct 2026

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Nice board. Unfortunate choice of pin for PSRAM select though. :( Perhaps a mod might be possible to change it to GP0.

Mick

Zilog Inside! nascom.info for Nascom & Gemini

fred777
Senior Member

Joined: 01/07/2021
Location: United Kingdom
Posts: 106

Posted: 12:15pm 10 Oct 2026

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Bodge done, PSRAM CS is now on GP0. A bit ugly but I'm happy with it

Will add some glue to keep the bodge wire fixed. And I kept GP12-19 free for a HDMI adapter.

Edited 2026-10-10 22:16 by fred777

Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 9181

Posted: 01:19pm 10 Oct 2026

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Exactly how I pictured it, but I'd have used yellow wire as I have some and I suspect the electrons like bright colours. :)

Just one point, did you preserve the pullup? If not you may find that you need one.
.
Edited 2026-10-10 23:21 by Mixtel90

Mick

Zilog Inside! nascom.info for Nascom & Gemini

fred777
Senior Member

Joined: 01/07/2021
Location: United Kingdom
Posts: 106

Posted: 01:31pm 10 Oct 2026

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No, the pin goes straight to GP0, I did the same with this board, and it didn't seem to matter. Perhaps it could fail in a noisy EMC environment.

Edited 2026-10-10 23:32 by fred777

ville56
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Joined: 08/06/2022
Location: Austria
Posts: 627

Posted: 04:12pm 10 Oct 2026

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fred777 said No, the pin goes straight to GP0, I did the same with this board, and it didn't seem to matter. Perhaps it could fail in a noisy EMC environment.

Without pullup it may work sometimes, but it is not reliable. There are phases of operation (e.g. booting up) where the CS pin of the PSRAM is floating. Believe me, I made the same error. Ended up that I couldn't even flash a new firmware anymore. Installed the pullup and all issues were gone.

73 de OE1HGA, Gerald

fred777
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Joined: 01/07/2021
Location: United Kingdom
Posts: 106

Posted: 05:42pm 10 Oct 2026

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Ok ok, another bodge

Don't even start about about how ugly this looks - I'm just glad the thing still works.

Edited 2026-10-11 03:43 by fred777

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