Can't seem to connect to Leonardo using avrdude command line

Other Hardware 3rd Party Boards
1

I'm trying to flash my leonardo from the command line using avrdude. after numerous programmer not responding errors, I then tried to simply connect to the board with the command:

./avrdude -patmega32u4 -C../etc/avrdude.conf -cavr109 -P/dev/cu.usbmodem...

However, I still get this message:

avrdude: butterfly_recv(): programmer is not responding
avrdude: butterfly_recv(): programmer is not responding
avrdude: butterfly_recv(): programmer is not responding
Found programmer: Id = ""; type = 
    Software Version = .; Hardware Version = .
avrdude: butterfly_recv(): programmer is not responding
avrdude: butterfly_recv(): programmer is not responding
avrdude: error: buffered memory access not supported. Maybe it isn't
a butterfly/AVR109 but a AVR910 device?
avrdude: initialization failed, rc=-1
         Double check connections and try again, or use -F to override
         this check.

avrdude: butterfly_recv(): programmer is not responding
avrdude: error: programmer did not respond to command: leave prog mode
avrdude: butterfly_recv(): programmer is not responding
avrdude: error: programmer did not respond to command: exit bootloader

I've tried different leonardos, usb ports, cables, and computers.

Any help with what to try next would be greatly appreciated.

2

(deleted)

3

Thanks for the reply. I've tried resetting the port (and I'm pretty sure I have it right). I've also tried to force bootloader with a reset double tap, but to no avail.

4

Here is what I just figured out:

As per this page: Leonardo | Nicholas Kell I need to trigger bootloader mode by making a serial connection with 1200bps and then immediately disconnecting. The reason I wasn't able to make this work by tapping the reset button is that the leonardo often grabs a new serial port name when it resets, so I would enter bootloader successfully, but when I went to flash, the port in my command line was no longer valid.

5

(deleted)

6

Wasn't ignoring you. The main issue was that the board wasn't entering bootloader mode. The port I was using originally was a valid port. It wasn't clear to me from your answer that this is what I was missing and why I should double tap reset.

In any case, I can't fathom how I would tap reset, scan for my correct port name, and edit my avrdude command in less than the 8 seconds it takes before bootloader mode exits, so I ended up doing it programmatically.