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RP2350 20-pin GPIO Expansion Card

The RP2350 20-pin GPIO Expansion Card is an open-source expansion card integrating a Raspberry Pi RP2350A microcontroller into a Framework expansion card, exposing 20 GPIO pins accessible from the laptop12. Designed by Tan Siret Akıncı (tansiret) and jerrymk, it was presented at Maker Faire Rome 2025 and certified by OSHWA (UID IT000024)23.

Design​

The card is built around the RP2350A, the dual-core Cortex-M33/RISC-V microcontroller from Raspberry Pi, with USB 1.1 connectivity to the host12. GPIO is broken out on both sides of the card on standard 2.54 mm (0.1") pitch pads, soldered horizontally1.

Pinout​

Front2:

LabelGPIOSPIUARTI²CADC
0GPIO0SPI0 RXUART0 TXI2C0 SDA
1GPIO1SPI0 CSnUART0 RXI2C0 SCL
2GPIO2SPI0 SCKI2C1 SDA
3GPIO3SPI0 TXI2C1 SCL
4GPIO4SPI0 RXUART1 TXI2C0 SDA
5GPIO5SPI0 CSnUART1 RXI2C0 SCL
6GPIO6SPI0 SCKI2C1 SDA
7GPIO7SPI0 TXI2C1 SCL
VCC3.3 V
RReset

Back2:

LabelGPIOSPIUARTI²CADC
29GPIO29ADC3
28GPIO28ADC2
27GPIO27I2C1 SDLADC1
GGround
13GPIO13SPI1 CSNUART0 RXI2C0 SCL
12GPIO12SPI1 RXUART0 TXI2C0 SDA
11GPIO11SPI1 TXI2C1 SCL
10GPIO10SPI1 SCKI2C1 SDA
9GPIO9SPI1 CSnUART1 RXI2C0 SCL
BBoot

Specifications​

SpecificationDetails
MCURaspberry Pi RP2350A (dual-core Cortex-M33 / RISC-V)12
GPIO18 general-purpose + VCC, GND, Reset, Boot2
Header pitch2.54 mm (0.1")1
USB1.1 (via RP2350 internal PHY)1
Design toolKiCad2
PCB0.8 mm (Type-C edge connector)1
Case3D-printable, designed by XenoCow (available on Printables)2
CertificationsOSHWA UID IT0000243
Sourcesemitov/rp2350-gpio-card (GitHub)2
LicenseCC BY 4.02
SponsorsNextPCB, DeepComputing2

Development​

The project was announced on the Framework Community forum in August 2025 and went through several design revisions before production1. The final design was produced and assembled by NextPCB12. DeepComputing sponsored a booth at Maker Faire Rome where the card was displayed alongside planned RISC-V based expansion cards12.

ProjectDescription
RP2040 Expansion CardJosh Cook's RP2040-based development card with Qwiic port
Google Coral Expansion CardML accelerator expansion card
LoRa Expansion CardLoRa wireless communication expansion card

Footnotes​

  1. RP2350 based GPIO expansion card — Framework Community (tansiret, August 2025) ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10

  2. semitov/rp2350-gpio-card — GitHub (CC BY 4.0) ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10 ↩11 ↩12 ↩13 ↩14

  3. OSHWA Certification IT000024 — Open Source Hardware Association ↩ ↩2