Victor Celer

The AT Emulator is a free tool, which can be used to emulate a communication device, like a modem. The AT interface can be accessed through the console, a TCP or telnet connection or a virtual COM port. The AT commands are typically used to interact with phones, modems and other communication ... [More] devices. Most GSM/3G/LTE/5G modems implement the AT command set over a serial port interface, for example: RS232 or USB. [Less]

Free minimalistic Java library, which can be used to interact with external devices over COM ports, for example: USB, virtual COM. The library has no external dependencies. Native drivers are included for 32-bit and 64-bit Windows and Linux. A pure Java driver is available as a fallback for other OS and architectures.