XIAO RA4M1 Simulator
the UNO R4's MCU in the XIAO footprint
Simulate the Seeed Studio XIAO RA4M1 in your browser for free: the Renesas RA4M1 of the Arduino UNO R4 Minima, with its 12-bit DAC, USB serial, GPIO, I2C and SPI wired to a live circuit.
Free plan · No install, no account · Runs in your browser
XIAO RA4M1 at a glance
The XIAO RA4M1 carries the same Renesas RA4M1 as the Arduino UNO R4 Minima, with a 12-bit DAC on A0. The in-browser engine boots the firmware Seeed's Renesas core produces; Serial is the USB CDC port and Serial1 sits on D6/D7, so UNO R4 code and libraries move over with a pin map check.
- Processor
- Renesas RA4M1, Cortex-M4 at 48 MHz
- Memory
- 32 KB SRAM · 256 KB flash
- Emulation
- ra4m1js (in-browser)
- Languages
- Arduino C++
- Plan
- Free
What you can do with the XIAO RA4M1 simulator
The board on the canvas is the real thing as far as your code is concerned: the same pins, the same buses, the same peripherals, wired to the same 100+ sensors, displays and actuators every other Velxio board talks to.
A real DAC
analogWrite on the DAC pin drives a true voltage, not a PWM, so the oscilloscope and the SPICE parts downstream see the waveform the board really produces.
Arduino C++ sketches
Write a sketch in the Monaco editor with library completion, compile it against the board's own Arduino core and run the real firmware binary. The Serial Monitor is the USB port.
GPIO, PWM and ADC
Drive LEDs, relays and servos, read buttons and potentiometers, dim with PWM. Every pin follows the board's real pin map, so what works here works on the hardware.
I2C, SPI and UART
Talk to OLEDs, IMUs, ADCs, RTCs and SD cards over the buses the board really has. Bus traffic runs through emulated peripherals, not through a shortcut.
Serial Monitor
USB CDC serial reaches the Serial Monitor at the sketch's baud rate, with input, timestamps and a plotter.
XIAO footprint
The thumbnail-sized XIAO pinout: D0 to D10 with the I2C, SPI and UART pads where every XIAO has them, so projects move between XIAO boards with a pin map check.
SPICE analog parts
Op-amps, transistors, regulators and passives simulate in real time with ngspice in the browser; the board's pins drive them and read the solved voltages back.
XIAO RA4M1 examples
Ready-to-run projects for this board from the gallery. Open one, read the sketch, press Run.
XIAO RA4M1: BlinkBlink an LED on D1 and count on the serial monitor - the first thing to try on the XIAO RA4M1, running on its own in-browser engine.
XIAO RA4M1: OLED over I2CWrite text to a 128x64 SSD1306 on the XIAO RA4M1's I2C pads (D4/D5) with U8g2, and mirror it on the serial monitor.
XIAO RA4M1: Knob and buttonRead a potentiometer on D0 and a pull-up button on D2 of the XIAO RA4M1; the button lights the LED and both values print on the serial monitor.
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Frequently asked questions
- Will Arduino UNO R4 sketches run on the XIAO RA4M1?
- Mostly yes: the MCU and the Renesas core are the same. Pins differ, so anything hard-coded to UNO pin numbers needs the XIAO map.
- Is the 12-bit DAC emulated?
- Yes. analogWrite on A0 drives a true 12-bit voltage into the SPICE circuit, visible on the oscilloscope.
- Is the XIAO RA4M1 free to simulate?
- Yes. It runs on the free plan, with no install and no account required.
- Is the XIAO RA4M1 simulator free?
- Yes. The XIAO RA4M1 runs on the free plan: open the editor, place the board and press Run. No install and no account are needed, and Velxio's editor and simulator core are open source under the GNU AGPLv3.
- Which languages can I use on the XIAO RA4M1?
- Arduino C++. The language is switched from the toolbar; the circuit on the canvas stays the same.
Ready to simulate the XIAO RA4M1?
Open the editor, place the XIAO RA4M1 from the picker, wire what you need and press Run.
Launch the XIAO RA4M1 simulator →