Arduino MKR Vidor 4000 Pinout: SAMD21 GPIO, FPGA, HDMI, MIPI, ADC, DAC and Interfaces

The Arduino MKR Vidor 4000 is unlike almost every other board in the MKR family because it combines a normal Arduino microcontroller with a substantial FPGA.

The board contains:

Arduino now marks the MKR Vidor 4000 as End of Life, but it remains an unusual and capable board for existing projects and FPGA experimentation.

Quick MKR Vidor 4000 Specifications

Feature	MKR Vidor 4000
Main MCU	SAMD21G18A Cortex-M0+
MCU clock	48 MHz
MCU Flash	256 KB
MCU SRAM	32 KB
Logic voltage	3.3 V
Analog inputs	7, A0-A6
ADC	8/10/12-bit selectable
True DAC	1 × 10-bit on A0
PWM from SAMD21	13 documented pins
FPGA	Intel Cyclone 10CL016
FPGA logic elements	16K
FPGA embedded RAM	504 kB
FPGA DSP multipliers	56 × 18×18-bit
External FPGA SDRAM	8 MB
FPGA configuration Flash	2 MB QSPI, with 1 MB allocated for user applications
FPGA header I/O	22 MKR-header pins
Additional FPGA I/O	25 programmable Mini PCIe connector pins
Video output	Micro HDMI
Camera	MIPI camera connector
Wireless	NINA-W102 Wi-Fi / Bluetooth
Secure element	ATECC508A
USB	Micro-USB / native SAMD21 USB
Battery	3.7 V single-cell Li-Po

The Most Important Concept: Two Programmable Devices

Most Arduino boards have one processor controlling the external pins.

Vidor has:

and the board routes the MKR-format I/O so the FPGA can participate in external pin functions as well.

This means a pin can be used as a conventional Arduino GPIO under SAMD21 control or as part of FPGA logic, depending on the design.

Do Not Drive the Same Pin from Both Sides

A shared pin must have one clear owner.

Do not configure:

on the same physical signal.

That creates electrical contention.

When moving a function into the FPGA, make sure the SAMD21 side is placed in a compatible high-impedance/input state unless the design intentionally requires otherwise.

3.3 V Logic

Both the microcontroller and FPGA side operate in a:

Do not treat MKR Vidor as a 5 V Arduino.

External:

• SPI;
• I2C;
• UART;
• parallel buses;
• analogue inputs;

must stay within the appropriate 3.3 V limits.

SAMD21 GPIO Current

Arduino’s current datasheet specifies:

with group-level current limits as well.

Use external drivers for:

• relays;
• motors;
• solenoids;
• high-current LEDs.

FPGA Output Current Is Configuration-Dependent

Do not assume FPGA pins are high-current outputs.

The allowed output current depends on the selected:

Arduino’s current Vidor datasheet summarises FPGA I/O current as:

depending on configuration.

Check the FPGA I/O standard and Quartus constraints for any custom design.

Main MKR Header Pin Mapping

The SAMD21 side follows the familiar MKR layout:

Arduino pin	SAMD21 pin	Main Arduino function
D0	PA22	GPIO / PWM
D1	PA23	GPIO / PWM
D2	PA10	GPIO / PWM
D3	PA11	GPIO / PWM
D4	PB10	GPIO / PWM
D5	PB11	GPIO / PWM
D6	PA20	GPIO / PWM
D7	PA21	GPIO / PWM
D8	PA16	GPIO / PWM / SPI COPI
D9	PA17	GPIO / SPI SCK
D10	PA19	GPIO / PWM / SPI CIPO
D11	PA08	GPIO / I2C SDA
D12	PA09	GPIO / PWM / I2C SCL
D13	PB23	GPIO / UART RX
D14	PB22	GPIO / UART TX

Analog Inputs A0-A6

The board exposes:

as analogue inputs.

They also have digital aliases:

Analog pin	Digital alias	SAMD21 pin	Main function
A0	D15	PA02	AIN0 / DAC0
A1	D16	PB02	AIN10
A2	D17	PB03	AIN11
A3	D18	PA04	AIN4 / PWM
A4	D19	PA05	AIN5 / PWM
A5	D20	PA06	AIN6
A6	D21	PA07	AIN7

ADC Resolution

Arduino supports:

ADC modes on the SAMD21.

For full 12-bit Arduino reads:

Then:

returns approximately:

A0 Is a True DAC Output

A0 is connected to:

and provides a genuine:

from the SAMD21.

DAC Example

SAMD21 PWM Pins

Arduino documents PWM on:

for:

under the normal SAMD21 Arduino core.

FPGA PWM Is Far More Flexible

The Cyclone 10 can synthesise custom PWM logic on FPGA-routed I/O.

Arduino’s datasheet describes all FPGA pins as configurable for functions such as:

• PWM;
• UART;
• SPI/QSPI;
• I2C;
• I2S;
• quadrature encoders;
• Sigma-Delta DAC;
• custom digital protocols.

This is not the same as calling:

on every pin.

The FPGA function has to exist in the loaded FPGA design.

Hardware UART

The normal SAMD21 UART is:

Use:

USB Serial

Because SAMD21 provides native USB:

so PC debugging does not consume the external UART.

I2C

The normal Arduino I2C bus is:

Use:

SPI

The main SAMD21 SPI interface is:

Use:

FPGA Can Implement Additional Serial Buses

The FPGA is not limited to the SAMD21’s peripheral count.

Arduino’s datasheet states that, depending on the loaded FPGA configuration, it can implement up to:

These are soft peripherals created in programmable logic.

Cyclone 10CL016 FPGA

The Vidor’s FPGA contains approximately:

This gives the board hardware resources for:

• parallel processing;
• custom protocol engines;
• high-speed counters;
• DSP;
• video pipelines;
• precise timing.

FPGA I/O Can Toggle Much Faster Than MCU GPIO

Arduino states that FPGA pins can toggle at:

depending on design and timing constraints.

This is fundamentally different from bit-banging GPIO in a normal Arduino loop.

FPGA Clocking

The FPGA system runs from:

and internal PLLs can generate higher clocks, with Arduino documenting operation up to roughly:

for FPGA logic.

8 MB External SDRAM

The Vidor includes:

for FPGA workloads such as:

• video framebuffers;
• image processing;
• audio buffers;
• large streaming pipelines.

This memory is associated with the FPGA subsystem and should not be confused with the SAMD21’s:

2 MB FPGA QSPI Flash

The FPGA subsystem also has:

for FPGA code/configuration.

Arduino states that approximately:

is allocated for user FPGA applications.

Micro HDMI Output

The board includes a:

connected to the FPGA subsystem.

This enables FPGA-generated:

• graphics;
• video;
• test patterns;
• text displays;
• custom visualisation.

The connector should not be confused with DisplayPort: Vidor uses Micro HDMI.

MIPI Camera Connector

The board also has a:

allowing image data to be routed into FPGA logic.

This supports projects such as:

• camera capture;
• QR-code processing;
• machine vision experiments;
• video filtering;
• real-time image pipelines.

Camera and HDMI Make Sense Because of the FPGA

The useful architecture is:

A 48 MHz Cortex-M0+ on its own would not be the natural processor for that workload.

Mini PCIe-Style Connector

The bottom edge includes a:

with up to:

plus power, ground and additional board signals.

Do Not Assume It Is a Normal PC PCIe Card

The connector uses the Mini PCIe mechanical format, but the exposed pins are primarily programmable FPGA I/O.

A standard PCIe interface does not magically appear merely because the connector has that shape.

The required protocol logic and electrical design must be implemented appropriately.

NINA-W102 Wireless Module

Wireless connectivity comes from:

which provides:

The NINA Module Is a Co-Processor

In normal Arduino use:

The NINA module contains its own processor and memory, but it is not simply extra SAMD21 application RAM.

ATECC508A Secure Element

The board includes:

for hardware-assisted:

• key storage;
• device identity;
• SHA-256/HMAC operations;
• elliptic-curve cryptography;
• secure cloud authentication.

RGB LED

Vidor includes an onboard:

in addition to the normal MKR user-LED functionality.

Its exact control path depends on the board support/FPGA design being used.

Native USB

The SAMD21 provides native:

through the board’s:

connector.

This supports programming, USB serial and compatible native USB device functions.

Li-Po Battery Support

The board supports a:

through its JST connector.

Arduino’s current datasheet specifies a recommended minimum battery capacity of:

Power Input

The detailed current Arduino power section states that VIN should be a regulated supply in approximately the:

range.

Do not treat MKR Vidor VIN like the wide-range VIN input of a classic UNO or Mega.

5 V and 3.3 V Rails

The board provides:

power connections.

The 5 V rail is a power rail only.

External logic should still be designed around:

Programming the FPGA

There are two broad approaches:

Arduino FPGA Libraries / Prebuilt Bitstreams

For supported Arduino examples, a prebuilt FPGA design can expose functions to the SAMD21 sketch.

Intel Quartus Prime

For custom hardware logic, Arduino’s documentation points to:

for HDL design, synthesis and FPGA programming workflows.

The FPGA Is Not Just a Faster Microcontroller

This distinction matters.

A microcontroller executes instructions:

An FPGA implements hardware logic that can run many functions simultaneously:

all operating in parallel.

Common Mistake 1: Applying 5 V to GPIO

The board is a:

Use level shifting for incompatible 5 V peripherals.

Common Mistake 2: Treating FPGA Pins as High-Current GPIO

FPGA drive strength depends on configuration.

Use external drivers for loads and observe the selected FPGA I/O standard.

Common Mistake 3: Driving a Pin from SAMD21 and FPGA Simultaneously

Give every shared physical signal one clear output owner.

Otherwise the devices can electrically fight each other.

Common Mistake 4: Assuming Every Pin Automatically Has FPGA PWM

The FPGA can implement PWM on many pins, but only if the loaded FPGA design contains the required PWM logic and routing.

Common Mistake 5: Calling the Video Port Mini DisplayPort

The official board provides:

not Mini DisplayPort.

Common Mistake 6: Assuming Mini PCIe Means Plug-and-Play PCIe

The connector primarily exposes FPGA-programmable signals in that mechanical format.

The FPGA design must implement whatever digital interface the application needs.

Common Mistake 7: Treating FPGA SDRAM as SAMD21 RAM

The SAMD21 still has:

while the:

belongs to the FPGA-oriented memory subsystem.

Common Mistake 8: Starting a New Product Without Noticing EOL Status

Arduino currently marks the MKR Vidor 4000:

It remains useful for existing hardware and learning, but long-term availability should be considered before using it in a new production design.

Quick SAMD21 Pin Reference

Quick Analog Reference

Quick Interface Reference

Final Thoughts

The MKR Vidor 4000 is best understood as:

The SAMD21 side gives familiar Arduino features:

while the FPGA side adds:

The most important pinout rules are:

For conventional SAMD21 MKR boards, see our MKR WiFi 1010 pinout guide, MKR Zero pinout guide and MKR WAN 1310 pinout guide.