Maybe you will be interested in a solution …
Application: IoT, “Smart home”, etc…
There is a developed and tested PLC modem. Work on any AC / DC lines.
Implementation on MCU STM32F303CBT6. Minimum parts for the analog part. Tested at a distance of 150-200 m. Estimated distance 300-350 m. Speed 19200 bps. I couldn’t think of anything cheaper and easier to manufacture.
There is an introductory kit as a set of boards (for voltage 9-24V; AC / DC; inverter 9-24-> 5V on the modem board):