ATTINY1626 serial UPDI not working

[cicco313]

Hello all and thanks a lot @SpenceKonde for this awesome work on megatiny core!
Currently i'm developing a new board and i've just put my hans on the first prototype, everything is working great except the updi programming of my attiny1626-xu microcontroller. I should have followed every instruction on the wiring between my usb to TTL converter (SH-UO9C2, based on the FT232RL) but i always get "Error while burning bootloader". I've used previously the same USBtoTTL converter to successfully flash another attiny1626-su roughly wired in a bread board. Could anyone please help my on that?

[cicco313]

Edit: USB to TTL on board resistors seems to be 330ohm.

Arduino: 1.8.19 (Windows 10), Board: "ATtiny3226/1626/826/426 w/Optiboot, ATtiny1626, 16 MHz internal, Enabled (default timer, TCB1), 4.2V (20 MHZ or less), Disabled/Disabled, UPDI on PA0, RST on PB4 (Optiboot for 1 sec after reset), Default (extr 1 sec if either reset pin enabled, otherwise always, 8 seconds), 8ms, TX:7 (PB2), RX:6 (PB3) (UART0 default pins), Master or Slave (saves flash and RAM), Default (doesn't print floats, 1.4k flash use), PB0-2, PA3-5 (0/2-series default), On all pins, with new implementation."

SerialUPDI

UPDI programming for Arduino using a serial adapter

Based on pymcuprog, with significant modifications

By Quentin Bolsee and Spence Konde

Version 1.2.3 - Jan 2022

Using serial port COM7 at 230400 baud.

Target: attiny1626

Set fuses: ['0:0x00', '1:0x00', '2:0x01', '5:0b11111110', '6:0x04', '7:0x00', '8:0x02']

Action: write

File: C:\Users\minul\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.10/bootloaders/hex/optiboot_tx2z_extr.hex

Traceback (most recent call last):

File "C:\Users\minul\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.10/tools/prog.py", line 286, in

main()

File "C:\Users\minul\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.10/tools/prog.py", line 128, in main

return_code = pymcuprog_basic(args, fuses_dict)

File "C:\Users\minul\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.10/tools/prog.py", line 201, in pymcuprog_basic

args_start)

File "C:\Users\minul\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.10\tools\libs\pymcuprog\pymcuprog_main.py", line 545, in _start_session

backend.start_session(sessionconfig)

File "C:\Users\minul\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.10\tools\libs\pymcuprog\backend.py", line 362, in start_session

sessionconfig.interface_speed)

File "C:\Users\minul\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.10\tools\libs\pymcuprog\programmer.py", line 83, in setup_device

options=self.options)

File "C:\Users\minul\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.10\tools\libs\pymcuprog\nvm.py", line 42, in get_nvm_access_provider

accessprovider = NvmAccessProviderSerial(transport, device_info, baud=frequency, options=options)

File "C:\Users\minul\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.10\tools\libs\pymcuprog\nvmserialupdi.py", line 54, in init

self.avr = UpdiApplication(port, baud, self.dut)

File "C:\Users\minul\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.10\tools\libs\pymcuprog\serialupdi\application.py", line 79, in init

datalink.init_datalink()

File "C:\Users\minul\AppData\Local\Arduino15\packages\megaTinyCore\hardware\megaavr\2.6.10\tools\libs\pymcuprog\serialupdi\link.py", line 44, in init_datalink

raise PymcuprogError("UPDI initialisation failed")

pymcuprog.pymcuprog_errors.PymcuprogError: UPDI initialisation failed

Error while burning bootloader.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

[cicco313]

Solved removing bypass capacitor on updi pin! :)