# Unable to Upload Code **URL:** \ **Category:** Uploading\ **Created:** [April 28, 2026, 10:27pm UTC](https://forum.arduino.cc/t/unable-to-upload-code/1441906 "2026-04-28T22:27:29Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![reemcscree](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/reemcscree/32/1269335_2.png) [@reemcscree](https://forum.arduino.cc/u/reemcscree)\ **Post date:** [April 28, 2026, 10:27pm UTC](https://forum.arduino.cc/t/unable-to-upload-code/1441906/1 "2026-04-28T22:27:29Z")
Hello, I have a couple microcontrollers I am using for a university project. They can be found here: [Romeo BLE - Control Board for Robot - Arduino Compatible - Bluetooth 4.0 - DFRobot](https://www.dfrobot.com/product-1176.html) However, I have not been able to upload code to them even after scouring the internet for solutions. We also ordered a new board and the same issue is present on that one. Here's the output from the IDE: ```arduino FQBN: arduino:avr:uno Using board 'uno' from platform in folder: C:\Users\Alex\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.7 Using core 'arduino' from platform in folder: C:\Users\Alex\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.7 Detecting libraries used... C:\Users\Alex\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\7.3.0-atmel3.6.1-arduino7/bin/avr-g++ -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10607 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR -IC:\Users\Alex\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.7\cores\arduino -IC:\Users\Alex\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.7\variants\standard C:\Users\Alex\AppData\Local\arduino\sketches\FC4597119EC542EDAC3E99376125A239\sketch\sketch_apr28a.ino.cpp -o nul Generating function prototypes... C:\Users\Alex\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\7.3.0-atmel3.6.1-arduino7/bin/avr-g++ -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10607 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR -IC:\Users\Alex\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.7\cores\arduino -IC:\Users\Alex\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.7\variants\standard C:\Users\Alex\AppData\Local\arduino\sketches\FC4597119EC542EDAC3E99376125A239\sketch\sketch_apr28a.ino.cpp -o C:\Users\Alex\AppData\Local\Temp\4131128941\sketch_merged.cpp C:\Users\Alex\AppData\Local\Arduino15\packages\builtin\tools\ctags\5.8-arduino11/ctags -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns --line-directives C:\Users\Alex\AppData\Local\Temp\4131128941\sketch_merged.cpp Compiling sketch... "C:\\Users\\Alex\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-g++" -c -g -Os -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -MMD -flto -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10607 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR "-IC:\\Users\\Alex\\AppData\\Local\\Arduino15\\packages\\arduino\\hardware\\avr\\1.8.7\\cores\\arduino" "-IC:\\Users\\Alex\\AppData\\Local\\Arduino15\\packages\\arduino\\hardware\\avr\\1.8.7\\variants\\standard" "C:\\Users\\Alex\\AppData\\Local\\arduino\\sketches\\FC4597119EC542EDAC3E99376125A239\\sketch\\sketch_apr28a.ino.cpp" -o "C:\\Users\\Alex\\AppData\\Local\\arduino\\sketches\\FC4597119EC542EDAC3E99376125A239\\sketch\\sketch_apr28a.ino.cpp.o" Compiling libraries... Compiling core... Using precompiled core: C:\Users\Alex\AppData\Local\arduino\cores\arduino_avr_uno_095fb8f8ea487b3855d6aeed3a9be729\core.a Linking everything together... "C:\\Users\\Alex\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-gcc" -Os -g -flto -fuse-linker-plugin -Wl,--gc-sections -mmcu=atmega328p -o "C:\\Users\\Alex\\AppData\\Local\\arduino\\sketches\\FC4597119EC542EDAC3E99376125A239/sketch_apr28a.ino.elf" "C:\\Users\\Alex\\AppData\\Local\\arduino\\sketches\\FC4597119EC542EDAC3E99376125A239\\sketch\\sketch_apr28a.ino.cpp.o" "C:\\Users\\Alex\\AppData\\Local\\arduino\\sketches\\FC4597119EC542EDAC3E99376125A239/..\\..\\cores\\arduino_avr_uno_095fb8f8ea487b3855d6aeed3a9be729\\core.a" "-LC:\\Users\\Alex\\AppData\\Local\\arduino\\sketches\\FC4597119EC542EDAC3E99376125A239" -lm "C:\\Users\\Alex\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-objcopy" -O ihex -j .eeprom --set-section-flags=.eeprom=alloc,load --no-change-warnings --change-section-lma .eeprom=0 "C:\\Users\\Alex\\AppData\\Local\\arduino\\sketches\\FC4597119EC542EDAC3E99376125A239/sketch_apr28a.ino.elf" "C:\\Users\\Alex\\AppData\\Local\\arduino\\sketches\\FC4597119EC542EDAC3E99376125A239/sketch_apr28a.ino.eep" "C:\\Users\\Alex\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-objcopy" -O ihex -R .eeprom "C:\\Users\\Alex\\AppData\\Local\\arduino\\sketches\\FC4597119EC542EDAC3E99376125A239/sketch_apr28a.ino.elf" "C:\\Users\\Alex\\AppData\\Local\\arduino\\sketches\\FC4597119EC542EDAC3E99376125A239/sketch_apr28a.ino.hex" "C:\\Users\\Alex\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-size" -A "C:\\Users\\Alex\\AppData\\Local\\arduino\\sketches\\FC4597119EC542EDAC3E99376125A239/sketch_apr28a.ino.elf" Sketch uses 444 bytes (1%) of program storage space. Maximum is 32256 bytes. Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes. "C:\Users\Alex\AppData\Local\Arduino15\packages\arduino\tools\avrdude\8.0.0-arduino1/bin/avrdude" "-CC:\Users\Alex\AppData\Local\Arduino15\packages\arduino\tools\avrdude\8.0.0-arduino1/etc/avrdude.conf" -v -V -patmega328p -carduino "-PCOM4" -b115200 -D "-Uflash:w:C:\Users\Alex\AppData\Local\arduino\sketches\FC4597119EC542EDAC3E99376125A239/sketch_apr28a.ino.hex:i" Avrdude version 8.0-arduino.1 Copyright see https://github.com/avrdudes/avrdude/blob/main/AUTHORS System wide configuration file is C:\Users\Alex\AppData\Local\Arduino15\packages\arduino\tools\avrdude\8.0.0-arduino1\etc\avrdude.conf Using port : COM4 Using programmer : arduino Setting baud rate : 115200 Error: programmer is not responding Warning: attempt 1 of 10: not in sync: resp=0x00 Error: programmer is not responding Warning: attempt 2 of 10: not in sync: resp=0x00 Error: programmer is not responding Warning: attempt 3 of 10: not in sync: resp=0x00 Error: programmer is not responding Warning: attempt 4 of 10: not in sync: resp=0x00 Error: programmer is not responding Warning: attempt 5 of 10: not in sync: resp=0x00 Error: programmer is not responding Warning: attempt 6 of 10: not in sync: resp=0x00 Error: programmer is not responding Warning: attempt 7 of 10: not in sync: resp=0x00 Error: programmer is not responding Warning: attempt 8 of 10: not in sync: resp=0x00 Error: programmer is not responding Warning: attempt 9 of 10: not in sync: resp=0x00 Error: programmer is not responding Warning: attempt 10 of 10: not in sync: resp=0x00 Error: unable to open port COM4 for programmer arduino Avrdude done. Thank you. Failed uploading: uploading error: exit status 1 ``` Nothing is connected to the board, when I attempt to upload the TX/RX lights blink I can communicate with the board just fine through the serial monitor I have tried: Multiple different systems with Windows and Linux Latest version, 2.2, 1.8.19 of Arduino IDE Multiple USB cables Switching to different ports in device manager Pressing reset button when uploading Resetting board with AT commands Probably some other stuff I'm forgetting Any help would be apricated, I'm at my wit's end. ---
**Author:** ![van\_der\_decken](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/van_der_decken/32/1006976_2.png) [@van\_der\_decken](https://forum.arduino.cc/u/van_der_decken)\ **Post date:** [April 28, 2026, 10:40pm UTC](https://forum.arduino.cc/t/unable-to-upload-code/1441906/2 "2026-04-28T22:40:06Z")
Have you followed the suggestions that can be found on the DFRobot forum for rectifying upload problems with this board? ---
**Author:** ![ptillisch](https://avatars.discourse-cdn.com/v4/letter/p/ad7895/32.png) [@ptillisch](https://forum.arduino.cc/u/ptillisch)\ **Post date:** [April 28, 2026, 10:43pm UTC](https://forum.arduino.cc/t/unable-to-upload-code/1441906/3 "2026-04-28T22:43:43Z")
Hi @reemcscree. In addition to the standard "Romeo BLE" board at the product page you linked, there are multiple other variants with similar names. For example: > **[Unlock Robotics Potential with Romeo V2 Control Board](https://www.dfrobot.com/product-844.html)** > > Discover how Romeo V2 enhances robotics with Arduino compatibility, integrated motor driver, and ATmega32u4 microcontroller. Start building today! Are you certain the board you are using is indeed the standard "Romeo BLE"? I ask because the **Tools \> Board \> Arduino AVR Boards \> Arduino Uno** configuration you have selected in Arduino IDE is correct for the standard "Romeo BLE", but would cause the upload to fail if you actually have a different board model connected to your computer. ---
**Author:** ![b707](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/b707/32/854321_2.png) [@b707](https://forum.arduino.cc/u/b707)\ **Post date:** [April 29, 2026, 12:59am UTC](https://forum.arduino.cc/t/unable-to-upload-code/1441906/4 "2026-04-29T00:59:07Z")
@reemcscree Judging by the error messages, you're trying to flash the board via Arduino IDE like a regular Uno. I think this won't work. As far as I can see from the board's schematic, the board USB is connected to the Bluetooth chip, not the ATMEGA. This means the AVR controller on this board can only be flashed either via Bluetooth or via the ICSP connector with a programmer. ---
**Author:** ![reemcscree](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/reemcscree/32/1269335_2.png) [@reemcscree](https://forum.arduino.cc/u/reemcscree)\ **Post date:** [April 29, 2026, 3:30am UTC](https://forum.arduino.cc/t/unable-to-upload-code/1441906/5 "2026-04-29T03:30:41Z")
So after looking through the DFRobot forum as you suggested I found a support email. Turns out I needed an older version of Arduino AVR Boards. For anyone else who runs into this problem: In the sidebar, open the boards manager (second icon). In it you should find Arduino AVR Boards. Install version 1.8.6 of this.