I cannot find a vendor for a ready-made or kit PC board that has a DB9 and an RS232 driver that outputs 3 or more RS232 levels, e.g., TD and RTS and DTR. And RS232-in for RD and CTS. And another DB9 RS232 port with just TD and RD.
anyone know of one? Better yet, a really low cost AVR board that has a mega128 or better and such an output.
I can breadboard one, but I'd like to purchase in low volume a ready-made PCB.