CircuiteraBefore you connect
Use a current desktop browser with Web Serial, such as Chrome or Edge, and a supported board such as Arduino Uno R3, a classic Nano configuration, or Mega 2560. Use a USB data cable: charge-only cables cannot transfer firmware. Some USB adapters need operating-system drivers or permissions. Close other applications that may be using the same serial port.
Verify first, then choose a port
Select the board and verify your sketch. Resolve compile errors before uploading. Connect the board, choose Connect board, and select the matching port in the browser prompt. Circuitera cannot grant serial permission on your behalf. If no port appears, check the cable, USB connection, operating-system recognition, and browser compatibility.
Upload and check the result
Press Upload after a successful build. Allow the upload and verification to complete before disconnecting the cable. Nano bootloader variants can require different settings, so compare the selection with your board. A handshake failure is not necessarily a physical disconnect; read the diagnostic before changing the wiring or reconnecting.
Observe the running sketch
After upload, use Serial Monitor at the baud rate chosen in Serial.begin(). A simple Blink sketch can also give a visible hardware check. If the program compiles but behaves unexpectedly, inspect pin assignments, power, and polarity. Circuit simulation is useful preparation, but real hardware remains the final check.