Serial monitor

For a supported microcontroller project, Run starts its emulator and connects serial output to Serial monitor. The monitor first shows the board’s boot text, followed by anything your sketch writes with Serial.print or Serial.println.

The starter’s setup() prints a greeting. Its loop then writes LED on and LED off as it changes GPIO 8. These messages are a quick way to confirm that the sketch is running, even before you add a simulated LED.

See the Hardware workbench for current screenshots and control explanations.

Use the Serial baud rate selector to match the value passed to Serial.begin() in your sketch. Serial send line ending controls what the monitor appends when you send text to the simulated board. The input field becomes available while the simulator is running. Auto-scroll follows new output; turn it off to inspect earlier lines. Timestamps adds a receive time to each line, and Clear Serial output clears the current view.

The baud rate, line ending, auto-scroll, and timestamp choices are saved with the project. Local drafts retain them across refreshes; save an account project to keep them with its account copy. UNO defaults to 9600 baud and other targets to 115200 unless saved. Use Stop simulator to stop a running or paused simulated program.

If the monitor stays disconnected, check that the selected target supports browser execution and that Run completed successfully. Use Build output to inspect compiler errors. Java projects use a terminal rather than this monitor.