Trying to dump flash for a Nano Every (ATMEGA4809)

[641i130]

I'm currently trying to dump the firmware for my 'nano every' but I keep getting 'programmer is not responding'.

avrdude -p m4809 -c avr910 -P/dev/ttyACM0 -U flash:r:"out.hex":r

How should I go about fixing my command?

[MCUdude]

If you're using the on-board USB connector, you can't use avr910 as the programmer, you'll have to use jtag2updi.

so:

avrdude -p m4809 -c jtag2updi -P/dev/ttyACM0 -U flash:r:"out.hex":r

However, the Nano every requires a "1200bps touch" in order to enter jtag2updi mode instead of the typical serial port.
This means that a serial port is opened at 1200bps, and then closed again before running Avrdude. On my mac, I've been using stty to do this, but it might be different on your computer.

$ PORT=/dev/ttyACM0; stty -f $PORT 1200 && avrdude -pm4808 -cjtag2updi -P$PORT -Uflash:r:out.hex:r

[641i130]

Ahh, that makes sense. Thank you!

Is it normal to see:

avrdude warning: attempt 1 of 10: sign-on command: status -1
avrdude warning: attempt 2 of 10: sign-on command: status -1
avrdude warning: attempt 3 of 10: sign-on command: status -1
avrdude warning: attempt 4 of 10: sign-on command: status -1
avrdude warning: attempt 5 of 10: sign-on command: status -1
avrdude warning: attempt 6 of 10: sign-on command: status -1
avrdude warning: attempt 7 of 10: sign-on command: status -1
avrdude warning: attempt 8 of 10: sign-on command: status -1
avrdude warning: attempt 9 of 10: sign-on command: status -1
avrdude warning: attempt 10 of 10: sign-on command: status -1
avrdude error: timeout/error communicating with programmer (status -1)
avrdude error: unable to open programmer jtag2updi on port /dev/ttyACM0

avrdude done.  Thank you.

Can you provide the stty version or website you got it off of? I don't think my Linux distro supports it.

[MCUdude]

Sorry, but the stty version that's bundled with macOS doesn't support -h, --help, -v or --version, but this is what I get when running the what command:

$ what /bin/stty
/bin/stty
	PROGRAM:stty  PROJECT:adv_cmds-172

However, I'm sure @mcuee has used stty for the exact same purpose, but on a computer running Linux. Maybe he can tell?

Anyways, here's what a working command should look like when connected to a genuine Nano Every:

$ PORT=/dev/cu.usbmodem14101; stty -f $PORT 1200 && ./avrdude -pm4809 -cjtag2updi -P$PORT -Uflash:r:out.hex:r
avrdude: AVR device initialized and ready to accept instructions
avrdude: device signature = 0x1e9651 (probably m4809)
avrdude: reading flash memory ...
Reading | ################################################## | 100% 5.22 s 
avrdude: writing output file out.hex

avrdude done.  Thank you.

[641i130]

AH! I figured it out. My version of stty must be newer:
PORT=/dev/ttyACM0; stty -F $PORT 1200 && avrdude -pm4809 -cjtag2updi -P$PORT -Uflash:r:out.hex:r
Thank you very much!

[MCUdude]

Great to hear you figured it out!

[mcuee]

More discussions for different OS here: Windows is the most troublesome.

• Flashing an Arduino Leonardo with AVRDUDE is troublesome #788

[MCUdude]

@mcuee we should probably gather various "tricks" like this in a Wiki page to make it easier to find for others that might run into the same problem(s).

[mcuee]

And yes for Linux. the correct option is to use -F.
https://man7.org/linux/man-pages/man1/stty.1.html