build a 2 way rs232 <-> rs485 interface to connect 8 or more rs232 interfaces to one bus system.

We need an easy solution to convert 8 or more RS232 interfaces to an RS485 bus. The system must add an address to the existing RS232 protocol when sending from rs232 to the RS485 but on the other side, when something is sent on the RS485 bus the system must strip the address and send it to the correct RS232 interface. This is to connect different serial rs232 communications to one bus. the solution must be stable with fixed connections, so no USB. we prefer esp32 but another micro controller can be used. When a pcb is needed we also need the pcb layout.