Simulator
An nRF52840 simulator that runs your firmware
LabWired runs unmodified nRF52840 firmware on a simulated nRF52840 DK, in the browser and in CI.
The lab below is the stock SEGGER RTT library on an nRF52840. The simulated probe drains the RTT buffer while the CPU runs. No UART is wired.
Live lab, running in your browser. Open the full lab →
What is simulated
- Clock, GPIO, UART, timers, I²C (TWIM), SPI, ADC (SAADC), PWM, watchdog and RTC. A booting firmware drives each one in CI.
- A BME280 temperature read through the unmodified Zephyr sensor driver (an on-demand external build).
- The RADIO TX handshake (TXEN, READY, START, END). The PR-gated OBD-II scanner test drives it.
- I²C completion events arrive after the wire time, not on the next instruction. This lets interrupt-driven Zephyr drivers boot.
What is left out
We list the gaps so you know when to reach for a bench.
- QDEC, AAR, ACL, COMP, CRYPTOCELL, I2S, LPCOMP and MWU are modelled, but no firmware or test exercises them.
- TWIS, SPIS, CCM, RNG, TEMP, ECB, GPIOTE, PPI, NVMC, NFCT, PDM, EGU, QSPI and USBD have unit tests only. No booting firmware drives them.
- USBREGULATOR is a thin VBUS-ready stub.
Sources
Checked on 22 October 2026 against:
Related
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