Programming using an RS232 (Serial) Cable in lieu of using USB (FTDI)
I have a question, is it possible to wire up a cable to directly interface an RS232 Serial Port on your computer to program the Microcontroller in lieu of using a USB interface?
It would seem to remove the FTDI dependency if you can just straight program from your serial port!
I know this can be done with other micro controllers (or at least, you used to be able to: eg, legacy PIC).
I am wondering what the Cable Pinout Diagram (Schematic) would be for the RS232 to interface it with the programming pins on the Board?
The problem is that true RS-232 uses signaling voltages that are incompatible with a arduino board and would cause damage unless one first converts the RS-232 voltage levels to serial TTL voltage levels.
But that aside there are a few arduino 'clone' type boards that are designed to directly plug into a PC RS-232 port. In fact my first introduction to arduino was via a kit version like this one: