HV programmer for DD series (and newer)

[iboguslavsky]

After much experimentation, I have build an HV programmer for the DD series (shameless plug: https://www.tindie.com/products/iboguslavsky/avr-dd-series-high-voltage-hv-programmer/)

[SpenceKonde]

Cool, does it work? Did you see the surprisingly low absolute max spec voltage on RESET pin?

[iboguslavsky]

Yes it does. Didn’t see the official spec on this one - but the lowest I was able to go was about 4.2V on the AVR64DD14 RESET pin for reliable programming.

BTW I’ve since built another one, with the USB UART on board

[SpenceKonde]

So how do you do the control from the computer side? AVRdude?

[iboguslavsky]

Yep, stock avrdude and jiggle DTR, ie to get to terminal: avrdude -c serialupdi -P /dev/ttyUSB0 -p avr16dd14 -xrtsdtr=low -t

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On Sat, May 31, 2025 at 5:21 PM Spence Konde (aka Dr. Azzy) < ***@***.***> wrote: *SpenceKonde* left a comment (SpenceKonde/DxCore#517) <#517 (comment)> So how do you do the control from the computer side? AVRdude? — Reply to this email directly, view it on GitHub <#517 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AF2Z243C2MQJIQ2VCLNYAU33BIMORAVCNFSM6AAAAAB53KS6LOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDSMRVG42TENBQGA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[amarotica]

Hi @iboguslavsky, I purchased your programmer (with UART on-board) and am still unsuccessful in reprogramming a chip after flashing. UPDI via your programmer works great initially, but I have not yet been able to reflash after I set PF6: Input & PF7: GPIO. I attempted your command above, but it times out while trying to contact the AVR chip. I'm using an AVR16DD20, and have attempted this on about 5 boards so far with no dice.