Uno r3 doesn't go into dfu mode

[WhiteCodeLua]

I'm trying to put my Uno r3 into dfu mode and frankly I'm going crazy trying. Even if I connect the jumper to the reset and ground pins it won't go into dfu mode.
I've tried downloading IDE 1.8.14 and 2.2.1 and it still doesn't work. I've also tried other connectors and had no success either.
I have a flipper zero and I used it as an isp programmer to load the bootloader "Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex" and when I load it, it simply bricks and I have to reinstall the bootloader again via the IDE using the flipper as programmer. I've lost count of how many times the arduino has bricked and I've had to reinstall the bootloader via the IDE.

I tried to check the bootloader using AVRDUDESS and it gave the following error

avrdude -c arduino -p m328p -P COM9 -b 115200 -U
flash:v:"C:\Users\WhiteC\Downloads\avrdude-v7.2-windows-x64\Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex":a
avrdude.exe: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.00s
avrdude.exe: Device signature = 0x1e950f (probably m328p)
avrdude.exe: verifying flash memory against C:\Users\WhiteC\Downloads\avrdude-v7.2-windows-x64\Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex:
avrdude.exe: input file C:\Users\WhiteC\Downloads\avrdude-v7.2-windows-x64\Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex auto detected as Intel Hex
Reading | ################################################## | 100% 0.33s
avrdude.exe: verification error, first mismatch at byte 0x0000
0xff != 0x90
avrdude.exe: verification error; content mismatch
avrdude.exe done. Thank you.

[sterretje]

The below two seem to contradict.

@WhiteCodeLua

avrdude -c arduino -p m328p -P COM9 -b 115200 -U

@WhiteCodeLua

Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex

The below is not the bootloader but the firmware for the 16U2. So the question is what you're trying to do. program the 16U2 or program the 328P? Based on the wiring in the video it seems to be the latter and you don't need DFU mode for that (to my knowledge).

@WhiteCodeLua

the bootloader "Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex"

Further this is probably outside my knowledge.

[WhiteCodeLua]

i want to turn my arduino uno r3 into a hid device, i've followed this tutorial, but I can't get past the part where it puts in dfu and flashes the "arduino-keyboard.hex" through the flip

https://www.instructables.com/How-to-Make-a-Arduino-HID-Keyboard/

[Juraj]

the Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex is for the 16u2 not for the 328p
dfu mode is used when you want to upload the Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex or othe firmware to the 16u2 over the USB (with Flip)

[toddnz]

You'll probably get better documentation from this project: GitHub - NicoHood/HID: Bring enhanced HID functions to your Arduino!

[WhiteCodeLua]

That's exactly what i want but it wong go into dfu and the only chip I can flash is the 328p through the isp programmer

[sterretje]

@WhiteCodeLua

but it wong go into dfu

What doesn't want to go in DFU mode? The 16U2 or the 328P?

And as @Juraj explained, you use the flip application in combination with dfu mode and not the programmer. You should also be able to program the 16U2 directly using its 6-pin header (the one that you were fiddling with in the video) and your programmer.

[WhiteCodeLua]

16u2, when i short the 2 correct pins the arduino just disconnect from the computer and connect back again, but still showing up as Arduino UNO

[WhiteCodeLua]

I read this post that you also answered, but I don't have another arduino to reprogram the 16u2.
I'm trying to get the flipper zero to recognize it, but I don't know if that's possible.
the post

[WhiteCodeLua]

[Solution] My problem is that I was connecting the wires to the wrong icsp2 pins, so the flipper zero wasn't recognizing the atmega16u2.
Correct pins layout:

After I connected it correctly it recognized it and so I was able to load the file Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex, after that it was just a matter of reconnecting the arduino to the computer and closing the short in the ground and reset pins that it entered dfu mode