powershell setup serial com port or bluetooth modem

openserialport.ps1

#make sure modem stuff 
#(hardware flow control  set up easy  seme as cmd console write-line read-line ...) example bluetooth modem
#if just serial port(USB-RS232)you may be set rts  enable 
#serial port very slow io you know you need infinite patience
$port = new-Object System.IO.Ports.SerialPort COM7,115200,None,8,one
$port.RtsEnable =$true
start-Sleep -m 1000
$port.Open()
# device init need some time 
#program enter sleep that make sure init task complete
start-Sleep -m 2000  

$port.WriteLine("at+cbc" +[char]13 +[char]13)  # need check out your modem spec siemems s45 [0xd][0xd][0xa]
 Start-Sleep -m 50
$port.ReadExisting()

#bluetooth modem and pc standard setup same 

$port = new-Object System.IO.Ports.SerialPort COM6
$port.Open()
$port.WriteLine("at+csq") 
start-sleep -m 50
$port.ReadExisting()