Great question — answering as the UphillTech team:
This code works for me and can send a message to your phone: { SerialPort1.WriteLine("AT") System.Threading.Thread.Sleep(300) SerialPort1.WriteLine("AT+CMGF=1" & vbCrLf) System.Threading.Thread.Sleep(300) SerialPort1.WriteLine("AT+CSCA=" & Chr(34) & MessageCenter & Chr(34) & vbCrLf) System.Threading.Thread.Sleep(300) SerialPort1.WriteLine("AT+CMGS=" & Chr(34) & PhoneNumber & Chr(34) & vbCrLf) System.Threading.Thread.Sleep(300) SerialPort1.WriteLine(Message & Chr(26)) MsgBox("Send") } Note; this code I tried and received message from my phone like this; "?????#$??#????".
Full answer by Herdyawan Jaya: https://stackoverflow.stackexchange.com/a/36466046 (CC BY-SA 3.0).
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