soylent is an "aspirational" (i.e. entirely untested, and designed by an electronics neophyte) hardware design for a tiny hardware modem for the TI Silent 707 briefcase teletype from the Texas Instruments Silent 700 series.
The teletype speaks 300-baud FSK using the Bell 103 dataset. The modem is designed to connect directly to the acoustic-coupler interface of the teletype, which supplies power to the modem as well as providing the FSK audio signal. The modem is designed to implement full-duplex translation between the FSK signal and a minimal RS-232 serial connection at 300bps.
The intention is for the tynsel project to supply a software implementation for the AVR microcontroller in the soylent design. For now, soylent serves mainly as a playground for the author to learn KiCad.