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Topic: Arduino clones with more RAM than Uno? (Read 6 times) previous topic - next topic

bratan


Or the 1284, which I assembled on a breadboard here:
http://www.gammon.com.au/forum/?id=11637
This has somewhat more RAM (16 Kb) and somewhat more program memory (128 Kb).

Nice tutorial!!!  Thanks a lot for sharing!

Build your code with the verbose option so you can locate the .elf file.
Then run nm on the .elf to see your symbols to be able to identify
what is using your RAM.

See the nm man page for more details but
here is a  sample useful command to get you started:
avr-nm -n -C -S *.elf > nm.out

In the nm output, the symbols with "B" near the bottom are the ones using up bss (RAM)
(This won't show the literal strings).

You can also get useful information from the objdump command.


--- bill

Thanks for the tip! I was wondering if it was possible to see how much RAM will program take before loading it to the chip.  I assume all these options are not available via standard IDE tho?  I couldn't find verbose, etc. What do I need to be able to run all these commands? Some kind of AVR studio?  Will it be compatible with .ino/.pde sketches and libraries I have?

It's not really a clone if it's a different chip, more like a spinoff.. I needed more ram when using the ENC28J60 ethernet chips. The TCP stack is in ram, rather than in the chip, so it takes most of the ram. So I used the Teensy++ 2.0, really cheap, uses the Arduino IDE just like I'm used to, and has like 8k of ram. Though nowadays, I'd use the Teensy 3.0, it's got 16k of ram and is cheap as dirt.

WOW I'm leaning more and more toward Teensy 3.0  It's just $20 and it has more ram than $50 Mega! So small too, and for this money I probably won't even have to bother with making my own PCB and 1284 chip...

Thanks all for the useful info. I love Arduino forums, everyone is so helpful! I learned so much!  :)
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bperrybap


Thanks for the tip! I was wondering if it was possible to see how much RAM will program take before loading it to the chip.  I assume all these options are not available via standard IDE tho?  I couldn't find verbose, etc. What do I need to be able to run all these commands? Some kind of AVR studio?  Will it be compatible with .ino/.pde sketches and libraries I have?

To use the verbose mode, if on pre 1.x IDE press the <SHIFT> key when building.
If on the newer IDE you have go to the [File]->[Preferences] dialog.

To run the commands it depends on what OS you use.
They are run from the command line which is why you have locate
the directory where the IDE is building images.
If you are stuck using windows, then the commands are there, they are just a bit harder to locate
as they are down in a directory under where the IDE is installed.


But before I'd jump ship to another board/device, particularly one that is a different
architecture and limited to 3v, I'd definitely make sure to understand what the real issue is
and know what it using all the RAM to make sure that there is not some other quick solution to solve
it. (like moving string literals to flash).

--- bill

Nick Gammon

Quote
I was wondering if it was possible to see how much RAM will program take before loading it to the chip.


Not really. The compiler can't know if you are going to do malloc a thousand times, for example. You can use some of the code around that reports the amount of free RAM after you loaded the program, that would give you a good guide if you don't do dynamic memory allocation (eg. use the String class).

dc42

From a post I saw a week or so ago, I have a feeling that the new version 1.5 IDE does report the amount of RAM allocated statically by your code.

Using dynamic memory allocation (including the String class) is a bad idea in small embedded systems.
Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

bperrybap


From a post I saw a week or so ago, I have a feeling that the new version 1.5 IDE does report the amount of RAM allocated statically by your code.

Using dynamic memory allocation (including the String class) is a bad idea in small embedded systems.


I'm not seeing it.
I only see the same stuff:
.cpp arduino munged files, .d dependency files, .o objects, .elf image file, and .hex image

I don't see any .lss or nm output files being created.

Do you have a link to that post?

--- bill

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