FLIP1 Device Signature read problem for ATmega16U2 on Arduino Uno

[mcuee]

Ref: The official Arduino Uno design uses ATmega16U2 (or ATmega8U2) for the USB to Serial function. The ATmega16U2 can be put into DFU mode and then you can use different host program to upload FW to the chip.
Ref: https://support.arduino.cc/hc/en-us/articles/4408887452434-Flash-USB-to-serial-firmware-in-DFU-mode

Somehow avrdude FLIP1 implementation has problem to read the device signature in this case. The reading (as well as writing) seems to be okay.

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c usbasp -qqp m16u2 
-U flash:r:read_16u2_usbasp.hex:i && echo OK
OK

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c flip1 -qqp m16u2 
-U flash:v:read_16u2_usbasp.hex:i && echo OK
avrdude_git.exe: Warning: Failed to read USB device string 1: Input/output error
avrdude_git.exe: Warning: USB bDeviceClass = 0 (expected 254)
avrdude_git.exe: Warning: USB bDeviceSubClass = 0 (expected 1)
avrdude_git.exe: Expected signature for ATmega16U2 is 1E 94 89
                 Double check chip, or use -F to override this check.

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c flip1 -qqp m16u2 
-F -U flash:v:read_16u2_usbasp.hex:i && echo OK
avrdude_git.exe: Warning: Failed to read USB device string 1: Input/output error
avrdude_git.exe: Warning: USB bDeviceClass = 0 (expected 254)
avrdude_git.exe: Warning: USB bDeviceSubClass = 0 (expected 1)
avrdude_git.exe: Expected signature for ATmega16U2 is 1E 94 89
OK

BTW, dfu-progammer works ok.

PS C:\work\avr\dfu-programmer-win-0.7.2> .\dfu-programmer atmega16u2 read 
>atmega16u2_read_dfu_programmer.hex
0%                            100%  Reading 0x3000 bytes...
[>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>]  Success
Dumping 0x1000 bytes from address offset 0x0.

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c usbasp -qqp m16u2 
-U flash:v:.\atmega16u2_read_dfu_programmer.hex && echo OK
OK

[mcuee]

Write has the same problem.

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c flip1 -qqp m16u2 -e && echo OK
avrdude_git.exe: Warning: Failed to read USB device string 1: Input/output error
avrdude_git.exe: Warning: USB bDeviceClass = 0 (expected 254)
avrdude_git.exe: Warning: USB bDeviceSubClass = 0 (expected 1)
avrdude_git.exe: Expected signature for ATmega16U2 is 1E 94 89
                 Double check chip, or use -F to override this check.

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c flip1 -qqp m16u2 -F -e && echo OK
avrdude_git.exe: Warning: Failed to read USB device string 1: Input/output error
avrdude_git.exe: Warning: USB bDeviceClass = 0 (expected 254)
avrdude_git.exe: Warning: USB bDeviceSubClass = 0 (expected 1)
avrdude_git.exe: Expected signature for ATmega16U2 is 1E 94 89
OK

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c flip1 -qqp m16u2 -F
 -U flash:w:.\Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex:i && echo OK
avrdude_git.exe: Warning: Failed to read USB device string 1: Input/output error
avrdude_git.exe: Warning: USB bDeviceClass = 0 (expected 254)
avrdude_git.exe: Warning: USB bDeviceSubClass = 0 (expected 1)
avrdude_git.exe: Expected signature for ATmega16U2 is 1E 94 89
OK

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c usbasp -qqp m16u2 
-U flash:v:.\Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex:i && echo OK
OK

[mcuee]

This may be an issue with the bootloader FW from Arduino.
https://github.com/arduino/ArduinoCore-avr/blob/master/firmwares/atmegaxxu2/Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex

Same problem with the hex file here on the official Arduino Leonardo board. It is also based on Arduino's bootloader implementation.
https://github.com/NicoHood/HoodLoader2/blob/master/avr/bootloaders/HexFiles/BootloaderDFU_atmega32u4_leo.hex

I just tried another DFU firmware on the official Arduino Leonardo board and it does not seem to have such issue.
https://www.pic-control.com/loading-arduino-bootloader-to-brand-new-atmel-microcontroller/

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c flip1 -p m32u4 -v

avrdude_git.exe: Version 7.0-20220719 (affe4cb)
                 Copyright (c) Brian Dean, http://www.bdmicro.com/
                 Copyright (c) Joerg Wunsch

                 System wide configuration file is "C:/work/avr/avrdude_test/avrdude_bin/avrdude.conf"

                 Using Port                    : usb
                 Using Programmer              : flip1
                 AVR Part                      : ATmega32U4
                 Chip Erase delay              : 9000 us
                 PAGEL                         : PD7
                 BS2                           : PA0
                 RESET disposition             : dedicated
                 RETRY pulse                   : SCK
                 Serial program mode           : yes
                 Parallel program mode         : yes
                 Timeout                       : 200
                 StabDelay                     : 100
                 CmdexeDelay                   : 25
                 SyncLoops                     : 32
                 PollIndex                     : 3
                 PollValue                     : 0x53
                 Memory Detail                 :

                                                   Block Poll               Page                       Polled
                   Memory Type Alias    Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
                   ----------- -------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
                   eeprom                 65    20     4    0 no       1024    4      0  9000  9000 0x00 0x00
                   flash                  65     6   128    0 yes     32768  128    256  4500  4500 0x00 0x00
                   lfuse                   0     0     0    0 no          1    1      0  9000  9000 0x00 0x00
                   hfuse                   0     0     0    0 no          1    1      0  9000  9000 0x00 0x00
                   efuse                   0     0     0    0 no          1    1      0  9000  9000 0x00 0x00
                   lock                    0     0     0    0 no          1    1      0  9000  9000 0x00 0x00
                   calibration             0     0     0    0 no          1    1      0     0     0 0x00 0x00
                   signature               0     0     0    0 no          3    1      0     0     0 0x00 0x00

                 Programmer Type : flip1
                 Description     : FLIP USB DFU protocol version 1 (doc7618)

avrdude_git.exe: Found VID=0x03eb PID=0x2ff4 at 001:058
avrdude_git.exe: Warning: USB bDeviceClass = 255 (expected 254)
    USB Vendor          : ATMEL (0x03EB)
    USB Product         : ATm32U4DFU (0x2FF4)
    USB Release         : 0.0.0
    USB Serial No       : 1.0.0
    USB max packet size : 32
avrdude_git.exe: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude_git.exe: Device signature = 0x1e9587 (probably m32u4)

avrdude_git.exe done.  Thank you.

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c flip1 -qqp m32u4 
-U .\blink_both\blink_fast_Teensy2.hex && echo OK
avrdude_git.exe: Warning: USB bDeviceClass = 255 (expected 254)
OK

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c flip1 -qqp m32u4
 -U flash:v:.\blink_both\blink_fast_Teensy2.hex && echo OK
avrdude_git.exe: Warning: USB bDeviceClass = 255 (expected 254)
OK

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c usbasp -qqp m32u4 
-U flash:v:.\blink_both\blink_fast_Teensy2.hex && echo OK
OK

[mcuee]

I will close this issue as invalid after a few days. Hopefully someone else can also confirm that this is an Arduino DFU bootloader issue as well.

Testing should be easy for those who have the Arduino Uno with ATmega16U2 as the USB chip (not clones using CH340/etc).

[MCUdude]

I can confirm that there's an issue with the ATmega16U2 (Arduino MEGA in my case) in when using flip1 on macOS.

ATmega16U2:

$ ./avrdude -cflip1 -patmega16u2

avrdude: Warning: Failed to read USB device string 1: Broken pipe
avrdude: Warning: USB bDeviceClass = 0 (expected 254)
avrdude: Warning: USB bDeviceSubClass = 0 (expected 1)
avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x940000
avrdude: Expected signature for ATmega16U2 is 1E 94 89
         Double check chip, or use -F to override this check.

avrdude done.  Thank you.

AT90USB162:

$ ./avrdude -cflip1 -pat90usb162

avrdude: Warning: USB bDeviceClass = 255 (expected 254)
avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e9482 (probably usb162)

avrdude done.  Thank you.

ATmega8U2:

$ ./avrdude -cflip1 -patmega8u2

avrdude: Warning: USB bDeviceClass = 255 (expected 254)
avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e9389 (probably m8u2)

avrdude done.  Thank you.

[MCUdude]

@mcuee do you know where I can find the "factory" DFU bootloader shipped with the ATmega16u2? The only chip I have is used on an Arduino MEGA, and it would be interesting to see if the latest version of the Atmel Flip bootloader would work better with Avrdude.

[mcuee]

do you know where I can find the "factory" DFU bootloader shipped with the ATmega16u2? The only chip I have is used on an Arduino MEGA, and it would be interesting to see if the latest version of the Atmel Flip bootloader would work better with Avrdude.

It is here, for both the Arduino Uno Rev 3 and Arduino Mega Rev 3. You can see they have not updated the DFU and USB Serial FW for 10 years..
https://github.com/arduino/ArduinoCore-avr/tree/master/firmwares/atmegaxxu2

I was hoping the following may be more updated, but they have the same issue.
https://github.com/NicoHood/HoodLoader2/tree/master/avr/bootloaders/HexFiles

Then I search the Arduino Core github issues list, they do not have such report. Apparently people may follow the official Arduino guide and use dfu-programmer or Microchip/Atmel FLIP, but not avrdude. BTW, dfu-util (another popular dfu related utility) does not work at all with the DFU bootloader at all.

All in all, I think this is a Arduino FW issue and not avrdude issue.

[mcuee]

Ref: arduino/ArduinoCore-avr#431

@MCUdude
There is another FW issue report above, on the USB serial portion but not on the DFU portion. The firmware is simply combination of the DFU FW and the USB-serial FW.

[mcuee]

@MCUdude

Latest official Microchip/Atmel DFU bootloader download is here. It has no issues with the device signature read for ATmega32U4 for the Arduino Leonardo.
https://ww1.microchip.com/downloads/en/DeviceDoc/doc7618.pdf (protocol and firmware source code)
https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/SoftwareLibraries/Firmware/megaUSB_DFU_Bootloaders.zip (hex files)

The link I mentioned earlier is using official Microchip bootloader hex file. But it has a typo --Microchip has hex file for AT90USB162 and not ATmega16U2. If I flash the AT90USB162 version FW-- I will have the same issue here.
https://www.pic-control.com/loading-arduino-bootloader-to-brand-new-atmel-microcontroller/

Maybe there is a way to rebuild the official Microchip DFU hex file for ATmega16U2 and the combine with the Arduino USB serial FW to fix this issue.
Ref: https://github.com/neoautus/Adelino/blob/master/Firmware/DFU/restore-to-factory.sh

[mcuee]

I will try the following later using Microchip Studio 7.
https://tewarid.github.io/2016/08/09/arduino-usb-dfu-firmware-from-scratch.html
https://github.com/tewarid/arduino-usb-dfu

Updates: done.
Result hex file:
ArduinoUsbDfu.hex.txt

And yes it fixed the issue.

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c usbasp -p m16u2 -U .\ArduinoUsbDfu.hex

avrdude_git.exe: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude_git.exe: Device signature = 0x1e9489 (probably m16u2)
avrdude_git.exe: NOTE: "flash" memory has been specified, an erase cycle will be performed
                 To disable this feature, specify the -D option.
avrdude_git.exe: erasing chip
avrdude_git.exe: reading input file ".\ArduinoUsbDfu.hex"
avrdude_git.exe: input file .\ArduinoUsbDfu.hex auto detected as Intel Hex
avrdude_git.exe: writing flash (16384 bytes):

Writing | ################################################## | 100% 0.06s

avrdude_git.exe: 16384 bytes of flash written
avrdude_git.exe: verifying flash memory against .\ArduinoUsbDfu.hex:
avrdude_git.exe: input file .\ArduinoUsbDfu.hex auto detected as Intel Hex

Reading | ################################################## | 100% 0.06s

avrdude_git.exe: 16384 bytes of flash verified

avrdude_git.exe done.  Thank you.

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c flip1 -p m16u2 
-U .\Arduino-usbserial-atmega16u2-Uno-Rev3.hex

avrdude_git.exe: Warning: USB bDeviceClass = 0 (expected 254)
avrdude_git.exe: Warning: USB bDeviceSubClass = 0 (expected 1)
avrdude_git.exe: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude_git.exe: Device signature = 0x1e9489 (probably m16u2)
avrdude_git.exe: NOTE: "flash" memory has been specified, an erase cycle will be performed
                 To disable this feature, specify the -D option.
avrdude_git.exe: erasing chip
avrdude_git.exe: reading input file ".\Arduino-usbserial-atmega16u2-Uno-Rev3.hex"
avrdude_git.exe: input file .\Arduino-usbserial-atmega16u2-Uno-Rev3.hex auto detected as Intel Hex
avrdude_git.exe: writing flash (4034 bytes):

Writing | ################################################## | 100% 0.39s

avrdude_git.exe: 4034 bytes of flash written
avrdude_git.exe: verifying flash memory against .\Arduino-usbserial-atmega16u2-Uno-Rev3.hex:
avrdude_git.exe: input file .\Arduino-usbserial-atmega16u2-Uno-Rev3.hex auto detected as Intel Hex

Reading | ################################################## | 100% 0.12s

avrdude_git.exe: 4034 bytes of flash verified

avrdude_git.exe done.  Thank you.

[mcuee]

Combined hex file readback.
atmega16u2_combined_dfufix_usbserial_remove_emptylines..hex.txt
atmega16u2_combined_dfufix_usbserial.hex.txt

[mcuee]

BTW, probably the following code is also more updated for the USB Serial codes.
https://tewarid.github.io/2016/08/10/arduino-usb-serial-firmware-from-scratch.html
https://github.com/tewarid/arduino-usb-serial

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c flip1 -p m16u2 -U .\ArduinoUsbSerial.hex

avrdude_git.exe: Warning: USB bDeviceClass = 0 (expected 254)
avrdude_git.exe: Warning: USB bDeviceSubClass = 0 (expected 1)
avrdude_git.exe: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude_git.exe: Device signature = 0x1e9489 (probably m16u2)
avrdude_git.exe: NOTE: "flash" memory has been specified, an erase cycle will be performed
                 To disable this feature, specify the -D option.
avrdude_git.exe: erasing chip
avrdude_git.exe: reading input file ".\ArduinoUsbSerial.hex"
avrdude_git.exe: input file .\ArduinoUsbSerial.hex auto detected as Intel Hex
avrdude_git.exe: writing flash (4174 bytes):

Writing | ################################################## | 100% 0.40s

avrdude_git.exe: 4174 bytes of flash written
avrdude_git.exe: verifying flash memory against .\ArduinoUsbSerial.hex:
avrdude_git.exe: input file .\ArduinoUsbSerial.hex auto detected as Intel Hex

Reading | ################################################## | 100% 0.12s

avrdude_git.exe: 4174 bytes of flash verified

avrdude_git.exe done.  Thank you.

ArduinoUsbSerial.hex.txt

And it still works.

PS C:\work\avr\avrdude_test\avrdude_bin> .\avrdude_git.exe -c arduino -P COM11 -p m328p 
-D -U .\hex\Blink.ino.standard.hex

avrdude_git.exe: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude_git.exe: Device signature = 0x1e950f (probably m328p)
avrdude_git.exe: reading input file ".\hex\Blink.ino.standard.hex"
avrdude_git.exe: input file .\hex\Blink.ino.standard.hex auto detected as Intel Hex
avrdude_git.exe: writing flash (924 bytes):

Writing | ################################################## | 100% 0.19s

avrdude_git.exe: 924 bytes of flash written
avrdude_git.exe: verifying flash memory against .\hex\Blink.ino.standard.hex:
avrdude_git.exe: input file .\hex\Blink.ino.standard.hex auto detected as Intel Hex

Reading | ################################################## | 100% 0.12s

avrdude_git.exe: 924 bytes of flash verified

avrdude_git.exe done.  Thank you.

`
BTW, I have also tried the alternative USB Serial FW here (claimes to be faster) and it also works fine with the updated DFU bootloader.
https://github.com/urjaman/fast-usbserial.git