Open Modem Firmware is an open source firmware implementation of a AFSK modem supporting 300, 1200 and 2400 baud operation, suitable for communication over a wide variety of analogue mediums, both radio and wired. The firmware is designed for and compatible with unsigned.io's OpenModem, but can be used on any similar build.

Complete modems are available from the unsigned.io shop, or can be build from scratch by referring to the schematics and documentation on the OpenModem page

• 300, 1200 and 2400 baud operation
• Full KISS TNC compatibility
• Secure in-modem AES-128 encryption
• SD card support
• Packet logging in PCAP format (WireShark compatible)
• Digitally adjustable input and output gain control
• Easy to use graphical config utility
• Supports standard GPS and bluetooth modules
• Supports large packets, 576 byte MTU
• Very large in-modem packet queue

Please refer to the manual and instructions posted at the OpenModem page. The default serial connection settings are 115200 baud, 8N1. For configuring the modem, please see the OpenModem Config Utility.