XIAO nRF52840 Sense Simulator
Nordic's nRF52840 with a live IMU, in your browser
Simulate the Seeed Studio XIAO nRF52840 Sense online for free: real Arduino firmware on an in-browser Cortex-M4F engine, a 6-axis IMU you tilt from the toolbar, and GPIO, ADC, PWM, I2C and SPI.
Free plan · No install, no account · Runs in your browser
XIAO nRF52840 Sense at a glance
The XIAO nRF52840 Sense runs on an engine that boots the firmware Seeed's own nRF52 Arduino core produces, so GPIO, ADC, PWM, Wire and SPI behave as they do over USB. The LSM6DS3TR-C IMU is live: press Sensors on the canvas toolbar, drag the Tilt pad, and the part reports that gravity at its real I2C address, 0x6A.
- Processor
- Nordic nRF52840, Cortex-M4F at 64 MHz
- Memory
- 256 KB RAM · 1 MB flash
- Emulation
- nrf52840js (in-browser)
- Languages
- Arduino C++
- Plan
- Free
What you can do with the XIAO nRF52840 Sense 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.
Live 6-axis IMU
Press Sensors on the canvas toolbar and drag the Tilt pad: the part reports that gravity at its real I2C address, and your orientation code reacts.
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.
What is not emulated
The radio (Bluetooth, Zigbee, Thread or WiFi, depending on the chip) is not modelled. Everything wired to the pins is; the wireless part of a project stays on the bench.
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 nRF52840 Sense examples
Ready-to-run projects for this board from the gallery. Open one, read the sketch, press Run.
XIAO nRF52840 Sense: BlinkBlink an LED on D1 and count on the serial monitor - the first thing to try on the XIAO nRF52840 Sense, running on its own in-browser engine.
XIAO nRF52840 Sense: OLED over I2CWrite text to a 128x64 SSD1306 on the XIAO nRF52840 Sense's I2C pads (D4/D5) with U8g2, and mirror it on the serial monitor.
XIAO nRF52840 Sense: Knob and buttonRead a potentiometer on D0 and a pull-up button on D2 of the XIAO nRF52840 Sense; the button lights the LED and both values print on the serial monitor.
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Frequently asked questions
- Is Bluetooth emulated on the XIAO nRF52840 Sense?
- No. The radio is not modelled; everything wired to the pins and the on-board IMU are. Prototype the sensing and the logic here, add the BLE part on the bench.
- How do I test the IMU without shaking a board?
- Press Sensors on the canvas toolbar and drag the Tilt pad. The IMU reports the matching acceleration over I2C, so orientation and gesture code reacts.
- Which Arduino core does the simulator use?
- Seeed's nRF52 core. The sketch compiles against it and the engine runs the resulting binary, so library behaviour matches the real board.
- Is the XIAO nRF52840 Sense simulator free?
- Yes. The XIAO nRF52840 Sense 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 nRF52840 Sense?
- Arduino C++. The language is switched from the toolbar; the circuit on the canvas stays the same.
Ready to simulate the XIAO nRF52840 Sense?
Open the editor, place the XIAO nRF52840 Sense from the picker, wire what you need and press Run.
Launch the XIAO nRF52840 Sense simulator →