import serial # Or: `import serial/utils`
for port in listSerialPorts():
  echo port

import serial # Or: `import serial/serialport`
let port = newSerialPort("COM1")
# use 9600bps, no parity, 8 data bits and 1 stop bit
port.open(9600, Parity.None, 8, StopBits.One)
# You can modify the baud rate, parity, databits, etc. after opening the port
port.baudRate = 2400
var receiveBuffer = newString(1024)
while true:
  let numReceived = port.read(receiveBuffer)
  discard port.write(receiveBuffer[0 ..< numReceived])

import serial # Or: `import serial/serialstream`
let port = newSerialStream("COM1", 9600, Parity.None, 8, StopBits.One, buffered=true)
while true:
  # Read a line from the serial port then write it back.
  port.writeLine(port.readLine())