Hardware details
Pinout
Click here for a high-resolution version of the pinout.
Pin details
The board labels its GPIO pins IO0-IO29 on the silkscreen, the same convention used on Soldered's other NULA boards, instead of the RP2040's raw "GPn" numbering. Several RP2040 GPIOs are consumed internally by the W55RP20 package and aren't exposed on the header at all, IO17 and IO20-IO25 don't appear anywhere on the board for this reason.
| Pin Marking | Peripheral options | Description |
|---|---|---|
| IO0 | UART0 TX, PWM0A | Digital I/O. |
| IO1 | UART0 RX, PWM0B | Digital I/O. |
| IO2 | I2C1 SDA, PWM1A | Digital I/O. |
| IO3 | I2C1 SCL, PWM1B | Digital I/O. |
| IO4 | SPI0 MISO, UART1 TX, PWM2A | Digital I/O. |
| IO5 | SPI0 CS, UART1 RX, PWM2B | Digital I/O. |
| IO6 | SPI0 SCK, PWM3A | Digital I/O. |
| IO7 | SPI0 MOSI, PWM3B | Digital I/O. |
| IO8 | PWM4A | Digital I/O. |
| IO9 | SD Enable, PWM4B | Digital I/O. Controls power to the onboard microSD card through a switch, see jumper details. |
| IO10 | SPI1 SCK, PWM5A | Digital I/O. Hardwired to the onboard microSD reader. |
| IO11 | SPI1 MOSI, PWM5B | Digital I/O. Hardwired to the onboard microSD reader. |
| IO12 | SPI1 MISO, PWM6A | Digital I/O. Hardwired to the onboard microSD reader. |
| IO13 | SPI1 CS, PWM6B | Digital I/O. Connects to the onboard microSD reader's CS line only if JP1 is bridged, see jumper details. |
| IO14 | PWM7A | Digital I/O. |
| IO15 | PWM7B | Digital I/O. |
| IO16 | PWM0A | Digital I/O. |
| IO18 | PWM1A | Digital I/O. |
| IO19 | PWM1B | Digital I/O. |
| IO26 | PWM5A | Analog input or digital I/O. |
| IO27 | PWM5B | Analog input or digital I/O. |
| IO28 | I2C0 SDA, PWM6A | Analog input or digital I/O. |
| IO29 | I2C0 SCL, PWM6B | Analog input or digital I/O. |
| VREF | - | ADC reference voltage. |
| RESET | - | Active-low reset input. |
| 3V3 | - | 3.3 V regulated output. |
| GND | - | Ground. |
| VCC | - | 5 V input from USB-C. |
| VBAT | - | Battery input, see battery support. |
Qwiic connector
Qwiic details and specifications
Learn more about Qwiic hardware compatibility and connector pinout.
Power supply
- USB-C powers the board (5 V input, exposed on the VCC pin).
- Onboard regulator provides 3.3 V for logic and peripherals.
- GPIO pins are 3.3 V logic only - not 5 V tolerant.
- The board can also run from a battery, see battery support below.
MicroSD card reader
The board has an onboard microSD card slot, connected over SPI1 (IO10-IO13). IO9 controls power to the card through an onboard switch (see JP3 and JP4 in jumper details), and IO13 only reaches the card's CS line if JP1 is bridged.
Battery support
The board has a JST battery connector and a VBAT pin, alongside a charge status indicator, so it can run from a single-cell Li-Ion/Li-Po battery instead of USB-C power.
Jumper details
This board contains hardware jumpers. See below for their locations and functions:
| Jumper | Default state | Function |
|---|---|---|
| JP1 | NO (Normally open) | Connects IO13 to the onboard microSD reader's CS line. |
| JP2 | NC (Normally closed) | 3.3 V I2C pull-up resistors for the Qwiic connector's SDA/SCL lines. |
| JP3 | NC (Normally closed) | Connects IO9 to the microSD power switch's control gate. |
| JP4 | NO (Normally open) | Bypasses the microSD power switch, tying the card's power rail directly to 3.3 V. |
| JP5 | NC (Normally closed) | Power LED (purple). |
| JP6 | NC (Normally closed) | Ethernet duplex status LED (yellow). |
| JP7 | NC (Normally closed) | Ethernet speed status LED (green). |
| JP8 | NC (Normally closed) | Ethernet link status LED (blue). |
| JP9 | NC (Normally closed) | Ethernet activity status LED (red). |
| JP10 | Selectable | Selects the W5500's PMODE0 pin: pull-up (3.3 V, default) or pull-down (GND). |
| JP11 | Selectable | Selects the W5500's PMODE1 pin: pull-up (3.3 V, default) or pull-down (GND). |
| JP12 | Selectable | Selects the W5500's PMODE2 pin: pull-up (3.3 V, default) or pull-down (GND). |
Together, JP10-JP12 set the W5500's PHY operation mode at power-up. Each jumper is independently selectable, so all eight combinations below are possible:
| JP10 (PMODE0) | JP11 (PMODE1) | JP12 (PMODE2) | Resulting mode |
|---|---|---|---|
| Pull-down | Pull-down | Pull-down | 10BT half-duplex, auto-negotiation disabled |
| Pull-up | Pull-down | Pull-down | 10BT full-duplex, auto-negotiation disabled |
| Pull-down | Pull-up | Pull-down | 100BT half-duplex, auto-negotiation disabled |
| Pull-up | Pull-up | Pull-down | 100BT full-duplex, auto-negotiation disabled |
| Pull-down | Pull-down | Pull-up | 100BT half-duplex, auto-negotiation enabled |
| Pull-up | Pull-down | Pull-up | Not used |
| Pull-down | Pull-up | Pull-up | Not used |
| Pull-up (default) | Pull-up (default) | Pull-up (default) | All modes capable, auto-negotiation enabled |
Dimensions
- Board dimensions: 68.6 × 58.4 mm (2.70 × 2.30 inch)
- Header pin holes: 1.5 mm
- Screw holes: Designed for M3 screws (3.2 mm diameter)
Soldered boards are LEGO compatible! 🧱
Hardware repository
Schematics, KiCad files, Gerber files and more can be found in the GitHub repository:
The hardware repository contains everything you need to understand, modify, or manufacture the board. The different output folders are versioned. You can check which board version you have by finding the version mark on the PCB.
Below is an overview of the available files.
CAD files
We use KiCad, an open-source PCB design tool. You can open and edit the .kicad_pro project file, which includes both the schematic and PCB layout.
The PANEL files are used internally for production.
Schematic
The OUTPUTS folder contains the schematic in .pdf format, exported from KiCad.
BOM (Bill of Materials)
The bill of materials (BOM) is provided in two formats:
- A standard
.csvtable, listing all components, part numbers, and values. - An interactive BOM (
.html) that visually highlights each component on the PCB, making it easy to locate and reference parts.
3D files
A 3D model of the PCB is available in .step format, allowing you to inspect the board design in CAD software.
Gerber files
Gerber files are essential for PCB manufacturing, as they contain precise instructions for each layer of the board. The repository includes standard Gerber outputs in a .zip file, such as:
- Copper layers (
.Cu.gbr) - Defines the traces and pads on the board. - Solder mask layers (
.Mask.gbr) - Specifies the protective solder mask. - Silkscreen layers (
.Silkscreen.gbr) - Contains text and component markings. - Paste layers (
.Paste.gbr) - Used for stencil fabrication in SMD assembly. - Drill files (
.drl) - Provides drilling coordinates for vias and holes. - Board outline (
.Edge_Cuts.gbr) - Defines the shape of the PCB. - Gerber job file (
.gbrjob) - Describes the set of Gerber files used for production.
These files are ready for fabrication and can be used in PCB manufacturing.
Compliance
The Compliance section includes important regulatory and safety documentation for this product. These files ensure compliance with relevant industry standards and legal requirements.
- CE - Certification document confirming compliance with EU safety, health, and environmental requirements.
- UKCA - UKCA (UK Conformity Assessed) certification for the UK market.
- Safety Instructions - Safety guidelines and precautions in English and in German.
- Info.txt - Contains product details such as SKU, country of origin, HS tariff code, and barcode.