The odyssey of getting my Funduino/Arduino UNO back to normal operation

Long, long time ago I had flashed the bootloader of my Funduino UNO.

When listing my USB devices it would appear as follows:

Bus 002 Device 017: ID 03eb:2042 Atmel Corp. LUFA Keyboard Demo Application

I had flashed a firmware to get an alternative to the makeymakey board with my own shield (basically with high-imedance resistors only). So I could not flash the ATmega328P microcontroller (in the socket) via the serial interface which is usually provided via the USB of the ATmega16U2. And unfortunately I didn’t have the old shield available anymore and the controller was constantly putting out data on the HID keyboard device which was quite annoying!

This page on sparkfun explains what a bootloader is, what it does and how it basically works:

Burning the bootloader via the Arduino IDE failed:


I wasn’t too sure if my AVRISP mkII was working correctly. I remembered that I’d has issues with it before – and I hadn’t used it for a long, long time!

Same error when trying to talk to avrdude directly via command line:

avrdude -c avrispmkII -p m16u2
avrdude: stk500v2_command(): command failed
avrdude: stk500v2_program_enable(): bad AVRISPmkII connection status: Target not detected
avrdude: initialization failed, rc=-1
 Double check connections and try again, or use -F to override
 this check.
avrdude done. Thank you.

Similar error for the ATmega328P with the other connector (using “avrdude -c avrispmkII -p m328p”). How about adding the port and verbose options?

$ avrdude -c avrispmkII -p m328p -P usb -v

avrdude: Version 6.0.1, compiled on Oct 21 2013 at 15:55:32
 Copyright (c) 2000-2005 Brian Dean,
 Copyright (c) 2007-2009 Joerg Wunsch

System wide configuration file is "/etc/avrdude.conf"
 User configuration file is "/home/maehw/.avrduderc"
 User configuration file does not exist or is not a regular file, skipping

Using Port : usb
 Using Programmer : avrispmkII
avrdude: usbdev_open(): Found AVRISP mkII, serno: 1337DEADBEEF
 AVR Part : ATmega328P
 Chip Erase delay : 9000 us
 BS2 : PC2
 RESET disposition : dedicated
 RETRY pulse : SCK
 serial program mode : yes
 parallel program mode : yes
 Timeout : 200
 StabDelay : 100
 CmdexeDelay : 25
 SyncLoops : 32
 ByteDelay : 0
 PollIndex : 3
 PollValue : 0x53
 Memory Detail :

Block Poll Page Polled
 Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
 ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
 eeprom 65 20 4 0 no 1024 4 0 3600 3600 0xff 0xff
 flash 65 6 128 0 yes 32768 128 256 4500 4500 0xff 0xff
 lfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
 hfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
 efuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
 lock 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
 calibration 0 0 0 0 no 1 0 0 0 0 0x00 0x00
 signature 0 0 0 0 no 3 0 0 0 0 0x00 0x00

Programmer Type : STK500V2
 Description : Atmel AVR ISP mkII
 Programmer Model: AVRISP mkII
 Hardware Version: 1
 Firmware Version Master : 1.12
 Vtarget : 0.0 V
 SCK period : 4.00 us

The error message can also be found on and (DE).

Relevant info: “-vvvv” gives a very verbose mode. Let’s assume my AVRISP mkII is broken. How to proceed? I’ve still got a working Arduino Leonardo lying around – let’s try to use it as an ISP: ArduinoISP –

Before loading the ArduinoISP sketch and resetting the board:

Bus 002 Device 023: ID 2341:8036 Arduino SA Leonardo (CDC ACM, HID)


Bus 002 Device 024: ID 2341:0036 Arduino SA

The two Arduino board are connected with the following pins:

  • power supply 5V and GND from the programmer to the target Arduino
  • SPI interface (MOSI on target pin 11, MISO on target pin 12, CLK on target pin 13)
  • reset pin of the target Arduino with a controlling GPIO of the programmer Arduino

Checkout the following diagram:

If pins with the same numbers were connected with each other – like those SPI pins – wouldn’t this conflict? If MISO was connected to MISO and MOSI was connected to MOSI? Both controllers might drive the same line?

It probably would! I have stumbled across the logic in the ArduinoISP sketch and had to define:


[Comment: “Uncomment following line to use the old Uno style wiring (using pin 11, 12 and 13 instead of the SPI header) on Leonardo, Due…”]

Avrdude didn’t complain about any wrong signatures anymore. I used:

$ avrdude -P /dev/ttyACM0 -c stk500v1 -b 19200 -F -v -v -p m328p

Back to the Arduino IDE, finally:


In a next step I compiled and downloaded the simple Blink example, that worked as well. Let’s try to unplug the Arduino Leonardo (the Arduino functioning as a programmer) and replug the USB connector to the Funduino/Arduino UNO. The LED still blinks after startup, however the UNO is still not available as a serial device to be programmed, but still the HID keyboard. The bootloader/firmware of the ATmega16U2 still needs to be flashed. The ATmega16U2 acts as a USB-serial bridge between the PC and the ATmega328P microcontroller.

Resetting the Arduino UNO connects the device in a different mode:

Bus 002 Device 062: ID 03eb:2fef Atmel Corp.

Then the dfu-programmer needs to be executed:

$ sudo dfu-programmer atmega16u2 erase

$ sudo dfu-programmer atmega16u2 flash Arduino-usbserial-atmega16u2-Uno-Rev3.hex 
4034 bytes used (32.83%)

$ sudo dfu-programmer atmega16u2 reset

… and power-cycling the board finally did the trick for me: the device is back available as serial interface:

Bus 002 Device 064: ID 2341:0043 Arduino SA Uno R3 (CDC ACM)

And now it can also be programmed via the Arduino IDE back again! 🙂



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