I want to know how exactly do I program (upload arduino sketches) an ATMEGA2560 which is boot loaded with an Arduino Bootloader using a FTDI programmer and an Arduino IDE, is there any capacitors/resistors required?

  • There is no such thing as a 'FTDI Programmer' what you most likely mean is programming the ATMEGA2560 over the a serial protocol like RS232.
    – d3l
    Oct 2, 2015 at 18:15
  • Yeah, sorry for my terminology. I have a FTDI breakout board link which I want to use to upload arduino sketches to the atmega2560.
    – Rakshith Gb
    Oct 2, 2015 at 18:31

1 Answer 1


If you have a bootloader, you just need to connect up four wires from the FTDI cable:

  • Pin 1 (black) -> Ground
  • Pin 2 (CTS) -> not connected
  • Pin 3 (Vcc) -> 5V
  • Pin 4 (TxD) -> Rx (Mega pin D0)
  • Pin 5 (RxD) -> Tx (Mega pin D1)
  • Pin 6 (green) -> not connected

FTDI connections

This will not auto-reset, so you will have to press (and release) the Reset button on the board at the moment that the sketch starts to upload.

How to make it auto reset?

What you should be able to do is connect RTS to Reset on the board, using a 0.1 µF capacitor (in series). I found in practice that this did not bring Reset low enough to trigger it - I'm not sure why, except maybe the board has a stronger pull-up resistor on /RESET than expected. That technique works for me on breadboard Arduinos.

Since it didn't work for me, I did not put it in my original answer. You could try that, and if it works, well and good.

  • I don't want to do that? How to make it auto reset? Oct 3, 2015 at 6:41
  • See amended reply. Is there any reason why you don't just use the USB interface? That usually works.
    – Nick Gammon
    Oct 3, 2015 at 6:46
  • I've fabricated a custom PCB with ATMEGA2560 mounted on it, I added your bootloader sketch and I'm trying to upload sketches to it using the arduino IDE, so that is why I'm using the FTDI chip to do this. Oct 3, 2015 at 8:43

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