I have a Uno board with the program in it, how to read it out

[kaojoy]

I have a Uno board with the program in it, how to read it out

[b707]

You can't do it, there is no source code inside the controller.

After compilation, a binary firmware file is loaded into the controller. The firmware has nothing common with the original sketch. Even if you can read it from the controller, there is no way to turn it back into program source code.

[TomGeorge]

Hi, @kaojoy
Welcome to the forum.

@kaojoy

I have a Uno board with the program in it, how to read it out

Did you write and upload the code that is now on the UNO?

How to get the best out of this forum

See also FAQ - Arduino Forum for general rules on forum behavior and etiquette. Hello, Welcome to the Arduino Forum. This guide explains how to get the best out of this forum. Please read and follow the instructions below. Being new here you might think this is having rules for the sake of rules, but that is not the case. If you don’t follow the guidelines all that happens is there is a long exchange of posts while we try to get you to tell us what we need in order to help you, which is frus…

Thanks.. Tom..

[StefanL38]

The sourcecode that is written gets compiled.

Compiling means all the human-readable words are translated to machine-readable numbers.
There is not a single letter left. Just a huge pile of numbers.
like this.

You can see letters in this screenshot but this is just because the binary numbers
are easier to read if the binary numbers are converted to hexadecimal numbers

[DVDdoug]

@StefanL38

Compiling means all the human-readable words are translated to machine-readable numbers.
There is not a single letter left. Just a huge pile of numbers.

Plus... Every C++ statement is usually translated to several machine-language instructions and some of the program "structure" can change.

...There is a direct correlation-translation between machine code and assembly language (AKA "assembler") and disassemblers exist to convert the machine code to assembly. As far as I know there is no disassembler for the Arduino. It can be done "manually" but it would "take forever".

There are also decompilers, but again probably not for the Arduino. But it's not exactly-like translating from French-to-English, and then back to French. All of the original variable names and all comments) are lost and some of the program structure may be different so you basically get a different C++ program that does the same thing.

In the real world decompiling is rarely useful. It's usually easer to figure-out what the program is doing and "reverse-engineer" it and write your own code that does the same thing.

[oldcurmudgeon]

You can get a disassembly fairly easily. If you have the source you can even get it annotated. For example

avr-objdump -S shows source code of everything but the sketch code [SOLVED]

Dear all, I'm trying to get a detailed disassembly output of my Arduino sketch; although I managed to have the raw disassembled code (based on avr-objdump -S, e.g. http://arduino.cc/forum/index.php/topic,46843.0.html), the sketch's source code never appears; on the other hand, I see some of the source code of the Arduino library (e.g. pinMode()). Tried with Arduino 1.0.3 and latest Git repo on Ubuntu Linux 12.10, but the results are the same. Here are the steps to reproduce the problem: loa…

[madmark2150]

Can you read out the existing compiled firmware binary to image out to clone to another board? I don’t need source, just multiple copies.

[sterretje]

@kaojoy

I have a Uno board with the program in it, how to read it out

The previous answers ignore the fact that the lock bits in the 328P processor might have been set. If YOU did upload the code to the Uno via USB, that will not be the case; but if somebody else uploaded that code via ICSP, they might have set the lock bits and you will never be able to read it out.

[TomGeorge]

Hi,
Until @kaojoy replies, we can only hope for more information the clear up the whys and wheres.

Tom...

[david_2018]

@madmark2150

Can you read out the existing compiled firmware binary to image out to clone to another board? I don’t need source, just multiple copies.

Yes, provided the lock bits have not been set to prevent this.

[madmark2150]

Good to know. Can the ide via the usb set the bit(s) and what bit am I looking for?

[b707]

@madmark2150

Can the ide via the usb set the bit(s)

no, it can't be set via usb

[stitech]

Background info: If a manufacturer sells a machine with a microcontroller and a program that took a lot of time to develop, he wants to block anyone else from reading his program. That’s what the lockbits are for.