Again at In0; After a small change in the "boards.txt" file, the feedback from the upload was completely different.
The change (speed from 115200 to 57600):
328.menu.clock.20MHz_external=External 20 MHz
328.menu.clock.20MHz_external.upload.speed=57600
#328.menu.clock.20MHz_external.upload.speed=115200
Very strange: avrdude sees "0x1e950f" as the signature, every sketch "readsignature.ino" shows "Your AVR signature is 1E 95 16". Who is right now?
The display of the upload:
Sketch uses 5450 bytes (16%) of program storage space. Maximum is 32256 bytes.
Global variables use 526 bytes (25%) of dynamic memory, leaving 1522 bytes for local variables. Maximum is 2048 bytes.
C:\Users\Rudol\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino18/bin/avrdude -CC:\Users\Rudol\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.3/avrdude.conf -v -V -patmega328pb -carduino -PCOM3 -b57600 -D -Uflash:w:C:\Users\Rudol\AppData\Local\Temp\arduino_build_402180/ReadSignature.ino.hex:i
avrdude: Version 6.3-20201216
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch
System wide configuration file is "C:\Users\Rudol\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.3/avrdude.conf"
Using Port : COM3
Using Programmer : arduino
Overriding Baud Rate : 57600
AVR Part : ATmega328PB
Chip Erase delay : 9000 us
PAGEL : PD7
BS2 : PC2
RESET disposition : dedicated
RETRY pulse : SCK
serial program mode : yes
parallel program mode : yes
Timeout : 200
StabDelay : 100
CmdexeDelay : 25
SyncLoops : 32
ByteDelay : 0
PollIndex : 3
PollValue : 0x53
Memory Detail :
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
eeprom 65 20 4 0 no 1024 4 0 3600 3600 0xff 0xff
flash 65 6 128 0 yes 32768 128 256 4500 4500 0xff 0xff
lfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
hfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
lock 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
calibration 0 0 0 0 no 1 0 0 0 0 0x00 0x00
signature 0 0 0 0 no 3 0 0 0 0 0x00 0x00
efuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
Programmer Type : Arduino
Description : Arduino
Hardware Version: 3
Firmware Version: 4.4
Vtarget : 0.3 V
Varef : 0.3 V
Oscillator : 28.800 kHz
SCK period : 3.3 us
avrdude: AVR device initialized and ready to accept instructions
An error occurred while uploading the sketch
Reading | ################################################## | 100% 0.00s
avrdude: Device signature = 0x1e950f (probably m328p)
avrdude: Expected signature for ATmega328PB is 1E 95 16
Double check chip, or use -F to override this check.
avrdude done. Thank you.