Can someone tell me what the resistors connected between the FT232RL DTR# pin and the ATmega168 reset pin, and the FT232RL RTS# pin and the ATmega168 reset pin on the Arduino Diecimila board are for?
They are labeled "R2 100_NM" and "R3 100_NM", which I assume means they are 100ohm resistors, but when I populate them on my design, the chip FT232RL doesn't respond.
On the actual Arduino board I have, R3 looks like a capacitor, and the spot where I think R2 should be is unpopulated.
Are R2 and R3 resistors? Are they meant to be 100ohm? What is their purpose?
I've circled the resistors in the image below:
That's for the famous auto reset feature. Actually, those are not resistors, but capacitors! And one of them is not on the PCB. I think the diecimila is only equipped with "R3", to auto reset on DTR.
--> playground article on that
Thanks for that, madworm.
Isn't labelling a capacitor with an 'R' instead of a 'C' a little confusing? Or does the 'R' stand for something other than "resistor"? Maybe "reset"?
Also, is the RTS#/R2 capacitor for a different purpose?
The actual eagle files have the correct capacitor symbol on DTR#; it looks like the PDF version is older, dating to a time when the team was still experimenting with how the auto-reset was going to work...