SparkFun Forums

[Mr.UNOwen]

I'm trying to idiot proof a board with serial communication to a PC. Is there a way to physically connect a FTDI so it only does serial communication without the ability to program the baord?

[jremington]

Yes. Leave off the reset connection.

You need only RX, TX and GND unless you are using the FTDI adapter to power the board.

[Mr.UNOwen]

So I don't see a reset, is it DTR? and if I recall, CTS (clear to send) is to remain grounded, right?

[jremington]

DTR on the FTDI adapter is connected via a capacitor to RESET on the MCU.

If you want to be absolutely certain that the board cannot be accidentally reprogrammed, use an ICSP programmer to burn the code. That erases the bootloader.