Jag köpte ett gäng nya Atmega328-PU. Eftersom det finns två varianter av detta mikrochip nämligen Atmega328p-pu och Atmega328-pu. P efter 328 innebär "pico-power" vilket betyder att den drar mindre ström. När man försöker bränna en bootloader ett icke pico-power-chip så får man felmeddelande om ogiltig signatur:

Expected signature for ATMEGA328P is 1E 95 0F Double check chip, or use -F to override this

Snabbaste sättet att lösa detta är att lägga till non-pico-power som en Arduino-typ. Gå till mappen där Arduino IDE är installerat. Öppna filen /hardware/tools/avr/etc/avrdude.conf. Lägg till detta:

#------------------------------------------------------------
# ATmega328
#------------------------------------------------------------

part
    id     = "m328";
    desc   = "ATMEGA328";
    has_debugwire = yes;
    flash_instr   = 0xB6, 0x01, 0x11;
    eeprom_instr = 0xBD, 0xF2, 0xBD, 0xE1, 0xBB, 0xCF, 0xB4, 0x00,
       0xBE, 0x01, 0xB6, 0x01, 0xBC, 0x00, 0xBB, 0xBF,
       0x99, 0xF9, 0xBB, 0xAF;
    stk500_devcode = 0x86;
    # avr910_devcode = 0x;
    signature    = 0x1e 0x95 0x14;
    pagel    = 0xd7;
    bs2      = 0xc2;
    chip_erase_delay = 9000;
    pgm_enable = "1 0 1 0 1 1 0 0 0 1 0 1 0 0 1 1",
     "x x x x x x x x x x x x x x x x";

    chip_erase = "1 0 1 0 1 1 0 0 1 0 0 x x x x x",
     "x x x x x x x x x x x x x x x x";

    timeout  = 200;
    stabdelay = 100;
    cmdexedelay = 25;
    synchloops = 32;
    bytedelay  = 0;
    pollindex = 3;
    pollvalue = 0x53;
    predelay = 1;
    postdelay = 1;
    pollmethod  = 1;

    pp_controlstack =
 0x0E, 0x1E, 0x0F, 0x1F, 0x2E, 0x3E, 0x2F, 0x3F,
 0x4E, 0x5E, 0x4F, 0x5F, 0x6E, 0x7E, 0x6F, 0x7F,
 0x66, 0x76, 0x67, 0x77, 0x6A, 0x7A, 0x6B, 0x7B,
 0xBE, 0xFD, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00;
    hventerstabdelay = 100;
    progmodedelay = 0;
    latchcycles   = 5;
    togglevtg   = 1;
    poweroffdelay = 15;
    resetdelayms = 1;
    resetdelayus  = 0;
    hvleavestabdelay  = 15;
    resetdelay   = 15;
    chiperasepulsewidth  = 0;
    chiperasepolltimeout = 10;
    programfusepulsewidth = 0;
    programfusepolltimeout = 5;
    programlockpulsewidth = 0;
    programlockpolltimeout = 5;

    memory "eeprom"
 paged   = no;
 page_size = 4;
  size    = 1024;
 min_write_delay = 3600;
 max_write_delay = 3600;
 readback_p1 = 0xff;
 readback_p2 = 0xff;
 read = " 1 0 1 0 0 0 0 0",
         " 0 0 0 x x x a9 a8",
         " a7 a6 a5 a4 a3 a2 a1 a0",
         " o o o o o o o o";

  write = " 1 1 0 0 0 0 0 0",
         " 0 0 0 x x x a9 a8",
   " a7 a6 a5 a4 a3 a2 a1 a0",
   " i i i i i i i i";

 loadpage_lo = " 1 1 0 0 0 0 0 1",
         " 0 0 0 0 0 0 0 0",
         " 0 0 0 0 0 0 a1 a0",
         " i i i i i i i i";

 writepage = " 1 1 0 0 0 0 1 0",
       " 0 0 x x x x a9 a8",
       " a7 a6 a5 a4 a3 a2 0 0",
       " x x x x x x x x";

 mode    = 0x41;
 delay   = 20;
 blocksize = 4;
  readsize  = 256;
    ;

    memory "flash"
 paged   = yes;
  size    = 32768;
  page_size = 128;
  num_pages = 256;
  min_write_delay = 4500;
 max_write_delay = 4500;
 readback_p1 = 0xff;
 readback_p2 = 0xff;
 read_lo = " 0 0 1 0 0 0 0 0",
     " 0 0 a13 a12 a11 a10 a9 a8",
     " a7 a6 a5 a4 a3 a2 a1 a0",
     " o o o o o o o o";

 read_hi = " 0 0 1 0 1 0 0 0",
     " 0 0 a13 a12 a11 a10 a9 a8",
     " a7 a6 a5 a4 a3 a2 a1 a0",
     " o o o o o o o o";

 loadpage_lo = " 0 1 0 0 0 0 0 0",
         " 0 0 0 x x x x x",
         " x x a5 a4 a3 a2 a1 a0",
         " i i i i i i i i";

 loadpage_hi = " 0 1 0 0 1 0 0 0",
         " 0 0 0 x x x x x",
         " x x a5 a4 a3 a2 a1 a0",
         " i i i i i i i i";

 writepage = " 0 1 0 0 1 1 0 0",
       " 0 0 a13 a12 a11 a10 a9 a8",
       " a7 a6 x x x x x x",
       " x x x x x x x x";

 mode    = 0x41;
 delay   = 6;
  blocksize = 128;
  readsize  = 256;

    ;

    memory "lfuse"
 size = 1;
 min_write_delay = 4500;
 max_write_delay = 4500;
 read = "0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0",
        "x x x x x x x x o o o o o o o o";

 write = "1 0 1 0 1 1 0 0 1 0 1 0 0 0 0 0",
          "x x x x x x x x i i i i i i i i";
    ;

    memory "hfuse"
 size = 1;
 min_write_delay = 4500;
 max_write_delay = 4500;
 read = "0 1 0 1 1 0 0 0 0 0 0 0 1 0 0 0",
        "x x x x x x x x o o o o o o o o";

 write = "1 0 1 0 1 1 0 0 1 0 1 0 1 0 0 0",
          "x x x x x x x x i i i i i i i i";
    ;

    memory "efuse"
 size = 1;
 min_write_delay = 4500;
 max_write_delay = 4500;
 read = "0 1 0 1 0 0 0 0 0 0 0 0 1 0 0 0",
        "x x x x x x x x x x x x x o o o";

 write = "1 0 1 0 1 1 0 0 1 0 1 0 0 1 0 0",
          "x x x x x x x x x x x x x i i i";
    ;

    memory "lock"
  size = 1;
 min_write_delay = 4500;
 max_write_delay = 4500;
 read = "0 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0",
        "x x x x x x x x x x o o o o o o";

 write = "1 0 1 0 1 1 0 0 1 1 1 x x x x x",
          "x x x x x x x x 1 1 i i i i i i";
    ;

    memory "calibration"
 size = 1;
 read = "0 0 1 1 1 0 0 0 0 0 0 x x x x x",
        "0 0 0 0 0 0 0 0 o o o o o o o o";
    ;

    memory "signature"
  size = 3;
 read = "0 0 1 1 0 0 0 0 0 0 0 x x x x x",
        "x x x x x x a1 a0 o o o o o o o o";
    ;
;

Hitta därefter filen /hardware/arduino/boards.txt och lägg till:

##############################################################

uno328.name=Arduino Uno w/ ATmega328 (non-P)
uno328.upload.protocol=arduino
uno328.upload.maximum_size=32256
uno328.upload.speed=115200
uno328.bootloader.low_fuses=0xff
uno328.bootloader.high_fuses=0xde
uno328.bootloader.extended_fuses=0x05
uno328.bootloader.path=optiboot
uno328.bootloader.file=optiboot_atmega328.hex
uno328.bootloader.unlock_bits=0x3F
uno328.bootloader.lock_bits=0x0F
uno328.build.mcu=atmega328
uno328.build.f_cpu=16000000L
uno328.build.core=arduino
uno328.build.variant=standard

Därefter ska det från Arduinos IDE se ut såhär:

Komponenter finns här:

• ATMEGA328-PU
• ATMEGA328P-PU (drar lite mindre ström)