AVR high voltage programmer

During this time, I was designing keyboards using Atmel's series of microcontrollers at90usb128x/64x and atmega32u4. One of the at90 microcontrollers was locked due to an incorrect fuse bit setting, which caused Progisp to be unable to flash the program. I checked online and found several ways to unlock it:

1. Use the output pin of the active crystal oscillator to the crystal oscillator input pin of the microcontroller. (The premise is that the fuse bit of the microcontroller is set to the external clock)
2. Use the crystal oscillator output pin of the normal microcontroller pair to the crystal oscillator input pin of the microcontroller with the wrong fuse bit. (The premise is that the fuse bit of the microcontroller is set to the external clock)
3. Use the normal microcontroller programming output clock to give it to the crystal oscillator input pin of the microcontroller with the wrong fuse bit. (The premise is that the fuse bit of the microcontroller is set to the external clock)

Since the fuse bit of my microcontroller is set to the internal clock, the above three methods are invalid, and I can only resort to the last straw - high-voltage programming. Most of the solutions found on Baidu only support high-voltage programming of low-end chips such as atmega8/16. After searching on Google, I found a solution that can support unlocking of most avr  microcontrollers https://www.instructables.com/id/How-to-fix-dead-atmega-and-attiny-avr-chips/This It was a plan given by a foreigner. My schematic is based on his basic design, mainly changed to support qfn64, qfn44 and qfp44 packages, which can be used for high-voltage programming of at90usb128x/64x and atmega32u4, and changed to use an external power supply. If you need to program dip28 or dip40 packaged chips, you can use his original design. For the pin connections of each chip, please refer to the instructions on this website and the chip manual. Notice:

1. My schematic diagram uses external common ground input voltages of 12v and 5v. Of course, you can integrate the voltage conversion into the board like the original author.
2. The atmega8 chip used to program other chips must first be written into the program given by the author, which is a .hex file. This can be done on another microcontroller. For details, please refer to another design of mine https://oshwhub.com/xiaoquana/ji-yu-MAX202ECSEhe-Atmega168vde-

This project has been shared to CSDN  https://blog.csdn.net/weixin_43607069/article/details/105679284