Memory Usage Issues

Here's some statistics from our library (trunk, revision 1580)

Dragonfly Library

   text    data     bss     dec     hex filename

    814       0       6     820     334 analog.o
    236       0       2     238      ee battery.o
   1892      16      43    1951     79f bom.o
    106       0       0     106      6a buzzer.o
   1424       0       0    1424     590 dio.o
    236       0       0     236      ec dragonfly_lib.o
    182       0       0     182      b6 eeprom.o
   1378       0       0    1378     562 encoders.o
    992       1       9    1002     3ea i2c.o
    904       6       0     910     38e lcd.o
   2088      13       3    2104     838 lights.o
    150       0       0     150      96 motor.o
    878       0       0     878     36e move.o
   1418      28       0    1446     5a6 odometry.o
    318       0       0     318     13e rangefinder.o
     22       0       0      22      16 reset.o
    594      23       0     617     269 serial.o
    188       0       5     193      c1 spi.o
    264       2       6     272     110 time.o

  14084      89      74   14247    37a7 (TOTALS)

Old Wireless Library

   text    data     bss     dec     hex filename

    276       0       0     276     114 sensor_matrix.o
    738       0     162     900     384 wireless.o
    248       0       0     248      f8 wl_basic.o
     56      10       0      66      42 wl_error_group.o
   2096      26       6    2128     850 wl_token_ring.o
   1944      48     120    2112     840 xbee.o          // I've been editing this file, and the data and bss sections should have been larger

   5358      84     288    5730    1662 (TOTALS)

User Code (Unit Tests as an example)

   text    data     bss     dec     hex filename

     22       0       0      22      16 main.o
    124      68       0     192      c0 test_analog.o
    186       0       0     186      ba test_dio.o
    334     298       0     632     278 test_eeprom.o
    226     108       0     334     14e test_encoders.o
      6       0       0       6       6 test_inits.o
     82     222       0     304     130 test_lcd.o
   2410      15       0    2425     979 test_lights.o
    386       0       0     386     182 test_motors.o
    366      20       0     386     182 test_rangefinder.o
    488     201       0     689     2b1 test_tokenring.o
    200     107       0     307     133 test_usb.o
    450      86       0     536     218 test_wireless.o
    238     138       0     376     178 test_xbee.o
   1910      40     120    2070     816 xbee.o

   7428    1303     120    8851    2293 (TOTALS)

Totals:

   text    data     bss     dec     hex filename

  26870    1476     482   28828    709c (TOTALS FROM ABOVE)
  30766    1650    1060   33476    82c4 main.elf

There's still some discrepancy between our measured total and the final size, which should be the avr libraries.

Here's a list of some things that are from the avr library in the elf symbol table:

data/bss:
   C.0.1714     10
   C.1.1715     10
   C.1.1418      6
   C.1.1452      6
   __clz_tab   256

total of 298 bytes

This still isn't enough to make up for the difference in the data/bss sections, but it's closer.

The good news is that we're currently at 2710 bytes in RAM (for the unit tests) out of 4096 bytes, so there is a little bit of leeway for the user code and the stack.

Note: Enabling debug flags greatly increases memory usage, since there's many error strings. In xbee.c alone, the data section is increased by 700 bytes. It may be necessary to clean this up, standardizing error strings and moving them into program space.