Sketch upload freezes during write I'm trying to upload a huge sketch to my Uno R2. It's compiling just fine but it fails to upload at 94% of writing to flash...

The program is so large because of a big array of data in a separate .h file:

#include &lt;avr/pgmspace.h&gt;
const unsigned char PROGMEM data[] = {
  0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x7f, 0x80, 0x7f, 0x80, 0x7f, 0x80, (etc...)


A test sketch with just 12 bytes of data uploads fine, so the problem is either with the size or some weird bug triggered by some of the data.

Unless i'm missing something, this should technically work.

Command:

    /home/hatagashira/.arduino-1.6.5/hardware/tools/avr/bin/avrdude -C/home/hatagashira/.arduino-1.6.5/hardware/tools/avr/etc/avrdude.conf -v -patmega328p -carduino -P/dev/ttyACM0 -b115200 -D -Uflash:w:/tmp/build8921209068074674980.tmp/program.cpp.hex:i


Output:

avrdude: Version 6.0.1, compiled on Apr 14 2015 at 19:04:16
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2009 Joerg Wunsch

         System wide configuration file is "/home/hatagashira/.arduino-1.6.5/hardware/tools/avr/etc/avrdude.conf"
         User configuration file is "/home/hatagashira/.avrduderc"
         User configuration file does not exist or is not a regular file, skipping

         Using Port                    : /dev/ttyACM0
         Using Programmer              : arduino
         Overriding Baud Rate          : 115200
         Setting bit clk period        : 5.0
         AVR Part                      : ATmega328P
         Chip Erase delay              : 9000 us
         PAGEL                         : PD7
         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 : Arduino
         Description     : Arduino
         Hardware Version: 3
         Firmware Version: 3.3
         Vtarget         : 0.3 V
         Varef           : 0.3 V
         Oscillator      : 28.800 kHz
         SCK period      : 3.3 us

avrdude: AVR device initialized and ready to accept instructions

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

avrdude: Device signature = 0x1e950f
avrdude: safemode: lfuse reads as 0
avrdude: safemode: hfuse reads as 0
avrdude: safemode: efuse reads as 0
avrdude: reading input file "/tmp/build8921209068074674980.tmp/program.cpp.hex"
avrdude: writing flash (30110 bytes):

Writing | ###############################################    | 94% 5.10savrdude: stk500_recv(): programmer is not responding
My two arduino nanos did flash and run the program correctly. I suspect a problem with the uno's serial communication but unwilling to troubleshoot further (i only have one uno). I decided to switch to the nano for further prototyping.