RP2350A Mini Molecule
General-purpose RP2350A castellated module — 20×36 mm, dual-core Arm Cortex-M33 / Hazard3 RISC-V MCU with 16 Mbit QSPI flash, USB, UART, SWD debug, and 4 ADC channels. 26 user-programmable GPIO/ADC pins exposed on castellated machine contacts (44 total contacts + 4 corner machine pins). Drop-in MCU module for Adom workcell designs.
How It Works
The RP2350A Mini is a minimal breakout of the Raspberry Pi RP2350A — all user-accessible GPIOs, USB, UART, SWD, ADC, and power are routed to castellated machine contacts around the perimeter. It is designed to be soldered onto a carrier board as a sub-module (like the RP2040 PICAN), providing the MCU brain for any workcell molecule. Power comes in through the corner machine pins (+3V3 on MP1/MP4). The on-board buck converter generates the 1.1V core voltage from 3.3V.
Overview
| Property |
Value |
| Molecule ID |
rp2350a-mini |
| Board Size |
20.0 × 36.0 mm |
| MCU |
RP2350A (QFN-60) — dual-core Cortex-M33 + Hazard3 RISC-V, 150 MHz |
| Flash |
W25Q16JVUXIQ — 16 Mbit (2 MB) QSPI |
| Crystal |
12 MHz (X322512MSB4SI) |
| Regulator |
On-chip buck converter (3.3V → 1.1V core, external 3.3 µH inductor) |
| USB |
USB 2.0 (D+/D- on machine contacts) |
| Machine Contacts |
44 contacts + 4 corner machine pins |
| KiCad Version |
7/8 |
Key ICs
| Ref |
Part |
Package |
Function |
| U1 |
RP2350A |
QFN-60 |
Dual-core MCU (Cortex-M33 + RISC-V) |
| U2 |
W25Q16JVUXIQ |
USON-8 |
2 MB QSPI flash |
Machine Contact Pin Mapping
4 corner machine pins + 44 castellated contacts on all 4 edges.
Corner Machine Pins
| Pin |
Net |
Function |
| MP1 |
+3V3 |
3.3V power input |
| MP4 |
+3V3 |
3.3V power input |
| MP2 |
GND |
Ground |
| MP3 |
GND |
Ground |
Left Edge (top to bottom)
| Contact |
Net |
Function |
| MC1 |
GND |
Ground |
| MC2 |
GPIO0 |
General purpose I/O |
| MC3 |
GPIO1 |
General purpose I/O |
| MC4 |
GND |
Ground |
| MC5 |
GPIO2 |
General purpose I/O |
| MC6 |
GPIO3 |
General purpose I/O |
| MC7 |
GPIO4 |
General purpose I/O |
| MC8 |
GPIO5 |
General purpose I/O |
| MC9 |
GND |
Ground |
| MC10 |
GPIO6 |
General purpose I/O |
| MC11 |
GPIO7 |
General purpose I/O |
| MC12 |
GND |
Ground |
| MC13 |
GPIO8 |
General purpose I/O |
| MC14 |
GPIO9 |
General purpose I/O |
| MC15 |
GPIO12 |
General purpose I/O |
Bottom Edge (left to right)
| Contact |
Net |
Function |
| MC16 |
GND |
Ground |
| MC17 |
GPIO13 |
General purpose I/O |
| MC18 |
GPIO14 |
General purpose I/O |
| MC19 |
GPIO15 |
General purpose I/O |
| MC20 |
GND |
Ground |
| MC21 |
SWCLK |
SWD debug clock |
| MC22 |
SWD |
SWD debug data |
Right Edge (bottom to top)
| Contact |
Net |
Function |
| MC23 |
GPIO16 |
General purpose I/O |
| MC24 |
GPIO17 |
General purpose I/O |
| MC25 |
GPIO18 |
General purpose I/O |
| MC26 |
GPIO19 |
General purpose I/O |
| MC27 |
GND |
Ground |
| MC28 |
Tx1 |
UART1 TX |
| MC29 |
Rx1 |
UART1 RX |
| MC30 |
GPIO22 |
General purpose I/O |
| MC31 |
GPIO23 |
General purpose I/O |
| MC32 |
GND |
Ground |
| MC33 |
GPIO24 |
General purpose I/O |
| MC34 |
GPIO25 |
General purpose I/O |
| MC35 |
GPIO26 / ADC0 |
ADC channel 0 |
| MC36 |
GPIO27 / ADC1 |
ADC channel 1 |
| MC37 |
GND |
Ground |
Top Edge (right to left)
| Contact |
Net |
Function |
| MC38 |
GPIO28 / ADC2 |
ADC channel 2 |
| MC39 |
GPIO29 / ADC3 |
ADC channel 3 |
| MC40 |
USB_D- |
USB data minus |
| MC41 |
USB_D+ |
USB data plus |
| MC42 |
GND |
Ground |
| MC43 |
BOOT |
Bootloader select |
| MC44 |
RST |
Reset |
GPIO Summary
| GPIO Range |
Count |
Available Functions |
| GPIO0–GPIO9 |
10 |
SPI, I2C, UART, PWM, PIO |
| GPIO10–GPIO11 |
2 |
(LED indicators, directly on module) |
| GPIO12–GPIO19 |
8 |
SPI, I2C, UART, PWM, PIO, HSTX (up to 300 Mb/s) |
| GPIO22–GPIO25 |
4 |
PWM, PIO |
| GPIO26–GPIO29 |
4 |
ADC0–ADC3 (12-bit, 500 ksps) |
GPIO10 and GPIO11 are used on-board for status LEDs and are not routed to contacts.
Status LEDs
| LED |
Color |
Function |
| D1 |
Red |
Power indicator |
| D2 |
Blue |
User LED (GPIO11) |
Programming
- USB bootloader: Bridge BOOT (MC43) to GND and power cycle — RP2350 enters USB mass storage mode. Copy a
.uf2 file to flash.
- SWD debug: SWCLK (MC21) and SWD (MC22) on the bottom edge. Use with a PiProbe or any CMSIS-DAP adapter.
- picotool:
picotool load firmware.uf2 -f over USB or SWD.
Power
| Rail |
Source |
Notes |
| +3V3 |
MP1/MP4 corner pins |
External 3.3V supply required |
| +1V1 |
On-chip buck (L1 = 3.3 µH) |
RP2350 core voltage, auto-generated |
Fabrication
- BOM:
jlcpcb/production_files/BOM-Molecule_RP2350A_Mini.csv
- CPL:
jlcpcb/production_files/CPL-Molecule_RP2350A_Mini.csv
- Gerbers:
jlcpcb/production_files/GERBER-Molecule_RP2350A_Mini.zip
3D Models
Molecule_RP2350A_Mini.glb — assembled board GLBMolecule_RP2350A_Mini.step — STEP modelRP2350_QFN60.step — RP2350 IC STEP model
