Well finally i can access to binaries into chip, im trying to read hex and i can, also write and i can because the lock bit is 0x00 but i cant modify the lock bit from 0x00 to 0xCC to protect the code, i presume that i must erase the chip then i can modify the lock bit from 0x00 to 0xCC but how i can erase the Atmega328p placed in Arduino Uno?
There's probably an AVRDUDE tutorial on the forum somewhere. If not, there are several elsewhere on the Internet. I haven't used it at the command line for over a decade so I can't say.
Yes, is AVRDUDE but with guy for windows so is called AVRDUDESS, is intuitive.
I tried to erase it with a blank code and can write it but dont work to reset lock bit to 0xFF, the chip is blank but the lock bit remain as 0x00.
Sorry, that's not in my area of expertise. Maybe another member will chime in.
Omg...
Sketch uses 31866 bytes (98%) of program storage space. Maximum is 32256 bytes.
And is debug 100% i cant increase more the free space to and nothing, just some text.
Because of high price of the imported Arduino UNO R3 colone in my country, I have made the following local clone (I have taken only the Bootloader; different form factor than that of the classic UNOR3) which costs half of the imported one. Will it be illegal and unethical for me to manufacture it and sell it? (I understand that the resources of arduino.cc are open source; so, anybody can copy it and sell it.)
You perform chip erase operation and then read the lock bits; they should be 0xFF.
How i can erase? i tried uploading blank code but dont work, i assume that i just write the code but dont affect to registers where are placed fuses and lock bit.
Please, post the pictures of you AVR Programmer and the AVRDUDESS Interface. These are my stuff:
Chip erase does not affect the settings of the fuse bits; they can only changed using Programmer. You may read the following Tables to know the purposes of the Fuse Bits and Lock Bits.
I use Arduino Uno as programmer via serial, it works and can read/write code and eeprom, but cant modify fuses and lock bit.
Dudes Ever launch a message in fuses and lock bit that cant modify the bits.
this the line that DUDES use to try.
>>>: avrdude -c arduino -p m328p -P COM3 -b 115200 -e -U flash:w:"C:\Users\migue_000\Documents\uno.hex":i -U lfuse:w:0x00:m -U hfuse:w:0x00:m -U efuse:w:0x00:m -U lock:w:0xFF:m
I know that Arduino works to read/write via DUDES because i compile the program as hex with arduino with some modification in some line text that dont affect the code, and then i write the hex to chip with DUDES and show the modification in text, so the arduino used as programmer work to read/write the flash and eeprom.
Can you make a test with arduino as programmer to test if you can modify the lock bit using Arduino as programmer?
If you can then im made some wrong.
and if you cant modify the lock bit, then Is needed an extern programmer.
Arduino as ISP programmer does not do Chip Erase operation as a seperate task. This programmer has no access to Fuse Bits and Lock Bits. You need a Universal ROM Programmer (Fig-1) or an AVR Programmer (Fig-2) to access these its. However, the RSTDISABL and SPIEN fuse bits can only be unprogrammed using Parallel ROM Programmer.
Figure-1: Universal ROM programmer
Figure-2: AVR Programmer
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This can be used?
USBASP AVR
I have no idea how to cnnect it with a 28-pin ATmega328P. It is better to buy one that has a 40-pin ZIF socket. Search the net. Where are you living?
There is a story about a plan to extract the hex code out of a locked chip (in this case an ATtiny85) in this thread. The main parts are between posts #32 (last sentence) and post #41 Tiny at85 CHIP INFO NEEDED - #32 by dss67
TL;DR
- Instead of attempting this the OP commissioned a re-write of the software.
- A Chinese company Contact Us - Shenzhen SiChi Technology quoted USD 275 to extract locked hex code.
- The process apparently is destructive. It appears they grind the top off the chip to get directly at the flash memory.
The black connector go to ICSP conector at Arduino (6 pins conector) placed near pin 1 of Atmega328.
You think that some student of the school will be capable to do that?
With block the chip vs copy i think is enough.
I knew that this topic would cause controversy, at no time, AT NO TIME, did i say that it was for dishonest reasons, thats why i didnt want to say what it was for, because there are always people like you who suspect even their mother.
The program ask for a pass from 6 to 32 chars, and im sure that some enlightened mind will try to use 123456, im sure 100%
Does your program allow the user to choose and reset their own password or will you preprogram the chips with passwords selected by the teachers?