$port = New-Object System.IO.Ports.SerialPort COM5, 115200, None, 8, 1
$port.ReadTimeout = 1000
try {
    $port.Open()
    Write-Host "Reading serial port COM5..." -ForegroundColor Cyan
    $startTime = Get-Date
    while (((Get-Date) - $startTime).TotalSeconds -lt 15) {
        try {
            $line = $port.ReadLine()
            Write-Output $line
        } catch [TimeoutException] {
            # normal timeout
        }
    }
} catch {
    Write-Error $_
} finally {
    if ($port -ne $null -and $port.IsOpen) {
        $port.Close()
    }
}