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AVR serial and parallel High-Voltage programmer

This programmer isn’t widely popular as usually is easier to use the ISP programming method. But sometimes if you need to disable the RESET pin and use it as a regular pin instead or you want to disable or restore SPI fuses that control the ISP programming method, then you will need a High-Voltage parallel programmer of AVR microcontrollers.

One of the programmers available on the wide internet is HVProg. This is a redesign of STK500 but without development board components. This programmer supports all available AVR microcontrollers in every programming mode and is compatible with AVRstudio.


In HVProg there are two versions of programmer:

The Basic-Version has separate connectors(6 Pin ISP, 10 Pin ISP, Serial HV programming, Parallel HV programming); for the different programming modes, it needs a stabilized 5V and 12V input voltages.

The Advanced-Version needs an un-stabilized input voltage of at least 15V (AC or DC). It has a 6 Pin ISP and a 20pin connector for ISP, parallel, and serial high-voltage programming.

The original ATMEL firmware is available in .ebn format that is only supported by AvrProg (included in AvrStudio “.\Stk500\stk500.ebn”). When you have the original Avr910 programmer you can directly flash the firmware in the At90s8535 or Mega8535.

  • Connect the ISP programming adapter with your computer and the ISP port on the HVProg board;
  • Mount the ‘Self-programming’ jumper to pin 1,2;
  • Connect the power supply;
  • Start AvrProg;
  • Select ‘stk500.ebn’ and set the appropriate fuses (high-frequency crystal for Mega8535);
  • Flash the firmware;
  • Disconnect power supply and then the programming adapter;
  • Mount the ‘Self-programming’ jumper back to pin 2,3.


  1. Has this HVProg been tested for High Volatge Serial\Parallel Programming (12 Volt programming environment) ??

  2. Authors say that HVProg has only been tested in 5V environments. I guess build it at your own risk.

  3. Dear Sir,

    Why the pins number of micro AT90S8535J-S in the basic-version(hvprog_03.gif) until 44 ??, but pins number of ATMega8535 only 40 (I use Mega8535).
    Please help me.

    Thanks for your attention.


  4. Dear Sir,
    Can the chip ATMEGA8535 be replaced by ATMEGA16?

  5. Can the chip ATMEGA8535 be replaced by ATMEGA16?

    ATMEGA8535 is pin compatible with Atmega16 but has less features.
    main differences are that ATMEGA8535 has 8k flash, 512b RAM, 512b EEPROM while ATMEGA16 has 16k flash, 1k RAM, 512b EEPROM. Atmega16 has different boot-loader area where page size is 64 words instead of 16. No read write section starts at 0x1C00 instead of 0xC00.
    Interrupt vectors uses 2byte addresses instead of 1. They have two different fuse bits – I think this shouldn’t affect.
    According to this I would say that probably moving from Atmega8535 to Atmega16 should work.
    Read more about commutability here

  6. Do you can write how is setting the fuse bits to use the MEGA8535 ?

  7. Dear nyomansad;

    ATMEGA8535 or At90S8535 in PLCC (or TQFP) has 44 pins as their 4pins are NOT connected! Please check the 8535 datashhet!

    Best Wishes!

  8. I Can’t Work With avr prog (.ebn)
    Please Help Me Or Convert ebn to hex
    Thank you

  9. This is a good product.
    Also refer FreeISP Programmer at http://www.deccanrobots.com

  10. I have made a ponyprog programmer. I had only 2 mega8L devices and tried programming one chip. It was easily verified and readable using ponyprog software. But I ended programming the RSTDISBL fuse bit.
    Now the problem is ponyprog software cannot read the device. We actually donot get AVR microcontrollers and that too are very costly in NPL. How can I get back my mega 8L with the least efforts and ease.
    Please suggest me ideas to make these device run again in ponyprog.

  11. Hello Mr. Scienceprog,

    I am getting ready to build this programmer as I need to restore a couple of Atmega16’s with bad fuse settings. I was wondering if you could point me to a link for the enclosure that you used for this project. I will be making my parts order from Mouser.com so if they have it it would be very convenient, but if not any link will do.


  12. Hi Sandeep,

    Unfortunately your only option is to use the High voltage programming mode to restore the RSTDISBL fuse. There is an easy-to-build programmer with complete instructions here:


    I hope you will be able to build the “basic” version featured with minimal efforts.

    I have had success programming the Mega8L the first time without problems, using AVRDUDE (on linux) from a STK200 compatible programming cable I wired myself. Look for the circuit here:


    I am able to re-program the flash, and I will take care not to mess with the fuses! I agree with you the AVRs are costly in most places. You might find the AT89S52 more suitable for some applications due to its low-cost and wide availability. You can program the 89S52 with a simple ISP cable you can wire up yourself, and a DOS software called AEC_ISP. Contact me if you need any help on this.

    Best regards,
    Krishna Teja


    sorry i can’t find the firmware
    could some one write the link for it…

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