For many years I've used an Uno with RST shorted to ground to connect serial ttl devices to computer USB ports - always worked fine.
I decided to do the same thing with a Nano, made a very nice pcb with a switch to ground the RST line one molex socket for the serial line and another for I2C connection so I could use it alternatively as an FTDI, a conventional nano controlled serial connection or a nano based I2C setup.
But alas, the basic function using the shorted RST doesn't transmit reliably to the TTL serial device.
I assume the USART/UART on the Nano must behave differently from the one on the UNO. Is this right?
And if you know, what do I need to look for to remake this thing using another micro-controller that's as small as the Nano?