AT28C64B AT28C256 EEPROM programmer

Copied from https://oshwhub.com/Oleg533/atmega-eeprom-programmer

Reference https://oshwlab.com/wagiminator/y-atmega-eeprom-programmer

Modify the USB-B interface to micro and type-c 

Using python3.8 to call the gui interface, it takes more than 1 second to read the 27 eeprom chip and less than 10 seconds to write the data.

Use Atmega8A to flash Arduino's BootLoader

Supported chips include ATmega328 ATmega168 ATmega88 ATmega48 ATmega8

Address   https://mcudude.github.io/MiniCore/package_MCUdude_MiniCore_index.json

There is no reset circuit when using ch340n. The reset is manually triggered during programming, that is, the upper two contacts of ICSP pin 6 (GND and RESET, below WR)

Based on the original code, the py code has been modified to remove the AT28Cxx chip locking/unlocking from the code for writing the chip. Two separate buttons are used to operate the chip's locking and unlocking (the locked 28 chip cannot be written and needs to be unlocked) )

In other words, if there is a lock chip, you need to click unlock first and then write to prevent accidental writing. You can re-lock the lock after writing to the chip.

Unlock:

  setByte (0x5555, 0xaa);
  setByte (0x2aaa, 0x55);
  setByte (0x5555, 0x80);
  setByte (0x5555, 0xaa);
  setByte (0x2aaa, 0x55);
  setByte (0x5555, 0x20);

Lock:

  setByte (0x5555, 0xaa);
  setByte (0x2aaa, 0x55);
  setByte (0x5555, 0xa0);

py compiled an exe file and put it in the attachment.  Two test options, 1k and 16k, were added.

The 28-pin chip can replace the 24-pin M27 chip (27C16 27C32), that is, the high-order address of 28 is left floating and connected to gnd, we is connected to vcc, only 2k or 4k data is burned, and the others are filled with FF, and then the 28-pin VCC is connected to 24 pins of 24 socket

If you change the program, you can also read the 24-pin 2716 2732