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MCUdude
Atmega328pb bootloader
I have a project where I use Atmega328p MCUs. As these shortages step in, I buy what can be bought. Atmega328pb for instance... Here comes the problem.
My bad as I didn't check the pinout and the datasheet. Just solder it on and tried to burn the bootloader. The board I used is the board that several 328p runs just fine. There is a 16MHz crystal, with 22pF caps. But there are VCC and GND on pins 3 and 6. On 328pb there are I2C1 pins. When trying to burn the bootloader using an Uno as an ISP and miniCore Atmega328pb in settings I get this error:
Arduino: 1.8.15 (Windows 10), Board: "ATmega328, Yes (UART0), EEPROM retained, 328PB, BOD 2.7V, LTO disabled, External 16 MHz"
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\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.1/avrdude.conf"
Using Port : COM5
Using Programmer : stk500v1
Overriding Baud Rate : 19200
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 : STK500
Description : Atmel STK500 Version 1.x firmware
Hardware Version: 2
Firmware Version: 1.18
Topcard : Unknown
Vtarget : 0.0 V
Varef : 0.0 V
Oscillator : Off
SCK period : 0.1 us
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.04s
avrdude: Device signature = 0x1e9516 (probably m328pb)
avrdude: erasing chip
avrdude: reading input file "0x3f"
avrdude: writing lock (1 bytes):
Writing | ################################################## | 100% 0.01s
avrdude: 1 bytes of lock written
avrdude: verifying lock memory against 0x3f:
avrdude: load data lock data from input file 0x3f:
avrdude: input file 0x3f contains 1 bytes
avrdude: reading on-chip lock data:
Reading | ################################################## | 100% 0.01s
avrdude: verifying ...
avrdude: 1 bytes of lock verified
avrdude: reading input file "0b11110101"
avrdude: writing efuse (1 bytes):
Writing | ################################################## | 100% 0.05s
avrdude: 1 bytes of efuse written
avrdude: verifying efuse memory against 0b11110101:
avrdude: load data efuse data from input file 0b11110101:
avrdude: input file 0b11110101 contains 1 bytes
avrdude: reading on-chip efuse data:
Reading | ################################################## | 100% 0.01s
avrdude: verifying ...
avrdude: 1 bytes of efuse verified
avrdude: reading input file "0b11010110"
avrdude: writing hfuse (1 bytes):
Writing | ################################################## | 100% 0.05s
avrdude: 1 bytes of hfuse written
avrdude: verifying hfuse memory against 0b11010110:
avrdude: load data hfuse data from input file 0b11010110:
avrdude: input file 0b11010110 contains 1 bytes
avrdude: reading on-chip hfuse data:
Reading | ################################################## | 100% 0.02s
avrdude: verifying ...
avrdude: 1 bytes of hfuse verified
avrdude: reading input file "0b11111111"
avrdude: writing lfuse (1 bytes):
Writing | ################################################## | 100% 0.02s
avrdude: 1 bytes of lfuse written
avrdude: verifying lfuse memory against 0b11111111:
avrdude: load data lfuse data from input file 0b11111111:
avrdude: input file 0b11111111 contains 1 bytes
avrdude: reading on-chip lfuse data:
Reading | ################################################## | 100% 0.02s
avrdude: verifying ...
avrdude: 1 bytes of lfuse verified
avrdude done. Thank you.
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\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.1/avrdude.conf"
Using Port : COM5
Using Programmer : stk500v1
Overriding Baud Rate : 19200
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 : STK500
Description : Atmel STK500 Version 1.x firmware
Hardware Version: 2
Firmware Version: 1.18
Topcard : Unknown
Vtarget : 0.0 V
Varef : 0.0 V
Oscillator : Off
SCK period : 0.1 us
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.05s
avrdude: Device signature = 0x1e9516 (probably m328pb)
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "C:\Users\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.1/bootloaders/optiboot_flash/bootloaders/atmega328pb/16000000L/optiboot_flash_atmega328pb_UART0_115200_16000000L_B5.hex"
avrdude: writing flash (32768 bytes):
Writing | ################################################## | 100% 0.00s
avrdude: 32768 bytes of flash written
avrdude: verifying flash memory against C:\Users\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.1/bootloaders/optiboot_flash/bootloaders/atmega328pb/16000000L/optiboot_flash_atmega328pb_UART0_115200_16000000L_B5.hex:
avrdude: load data flash data from input file C:\Users\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.1/bootloaders/optiboot_flash/bootloaders/atmega328pb/16000000L/optiboot_flash_atmega328pb_UART0_115200_16000000L_B5.hex:
avrdude: input file C:\Users\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.1/bootloaders/optiboot_flash/bootloaders/atmega328pb/16000000L/optiboot_flash_atmega328pb_UART0_115200_16000000L_B5.hex contains 32768 bytes
avrdude: reading on-chip flash data:
Reading | ################################################## | 100% 0.00s
avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x7e00
0x00 != 0x01
avrdude: verification error; content mismatch
avrdude done. Thank you.
Error while burning bootloader.
This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.
Should I cut those traces? Did I bricked the MCU? Can I use this MCU as a drop in replacement for a 328p?
I would perhaps first try to replace those 22pF caps with 10 or 15 pF ones.
Long story short, The 328PB's bigger brother is the ATmega324PB, and these are very similar internally. A major drawback to these parts is that they don't have any crystal "full swing oscillator" option anymore, which means that their external clock circuity may be very picky and can randomly stop working or not matched correctly, sometimes even weeks of operation.
A while ago I designed a commercial board where a 324PB was chosen because it had more IO than 324P. I used the same external oscillator as I always do, and there were 100 boards manufactured. All of these had to be recalled to have their external clock circuitry replaced. Once I figured out the correct values, it has never been an issue anymore.
If new capacitors don't work, try using a different programmer type, for instance, a USBasp or USBtinyISP. The additional pins shouldn't cause an issue as long as they're not configured as outputs. I do have an Atmega328PB based board, and I've never had any issues bootloading it.
Tried 18pF and 8.2pF. Didn't work. I don't have the values you suggested. I think I will get them next week.
For programming the bootloader, I use Arduino as ISP. Tried both programmers you suggested but no luck. I always get the same message as above. The Schematic is the same as for 328p. That said, one 100nF from Reset to DTR. One 10K from Reset to 5V, 16MHz crystal, and two 22pF caps. With this barebone setup, I never had a single issue with regular 328p.
Must try 10 and 15pF.
Ok, I tried 10pF and 15pF. With Arduino as ISP I ended the same as above.
While using USBTiny I get this:
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\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.3/avrdude.conf"
Using Port : usb
Using Programmer : usbtiny
Setting bit clk period : 32.0
avrdude: usbdev_open(): Found USBtinyISP, bus:device: bus-0:\\.\libusb0-0001--0x1781-0x0c9f
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 : USBtiny
Description : USBtiny simple USB programmer, http://www.ladyada.net/make/usbtinyisp/
avrdude: programmer operation not supported
avrdude: Setting SCK period to 32 usec
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.01s
avrdude: Device signature = 0x1e9516 (probably m328pb)
avrdude: erasing chip
avrdude: Setting SCK period to 32 usec
avrdude: reading input file "0x3f"
avrdude: writing lock (1 bytes):
Error while burning bootloader.
Writing | ################################################## | 100% 0.01s
avrdude: 1 bytes of lock written
avrdude: verifying lock memory against 0x3f:
avrdude: load data lock data from input file 0x3f:
avrdude: input file 0x3f contains 1 bytes
avrdude: reading on-chip lock data:
Reading | ################################################## | 100% 0.00s
avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x0000
0x00 != 0x3f
avrdude: verification error; content mismatch
avrdude done. Thank you.
I will try USBAsp later
This is from USBAsp:
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\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.3/avrdude.conf"
Using Port : usb
Using Programmer : usbasp
Setting bit clk period : 32.0
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 : usbasp
Description : USBasp, http://www.fischl.de/usbasp/
avrdude: set SCK frequency to 16000 Hz
avrdude: warning: cannot set sck period. please check for usbasp firmware update.
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.00s
avrdude: Device signature = 0x1e9516 (probably m328pb)
avrdude: erasing chip
avrdude: set SCK frequency to 16000 Hz
avrdude: warning: cannot set sck period. please check for usbasp firmware update.
avrdude: reading input file "0x3f"
avrdude: writing lock (1 bytes):
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\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.3/avrdude.conf"
Using Port : usb
Using Programmer : usbasp
Setting bit clk period : 32.0
AVR Part : ATmega328PB
Chip Erase delay : 9000 us
PAGEL : PD7
BS2 : PC2
RESET disposition : dedicated
Writing | ################################################## | 100% 0.00s
avrdude: 1 bytes of lock written
avrdude: verifying lock memory against 0x3f:
avrdude: load data lock data from input file 0x3f:
avrdude: input file 0x3f contains 1 bytes
avrdude: reading on-chip lock data:
Reading | ################################################## | 100% 0.00s
avrdude: verifying ...
avrdude: 1 bytes of lock verified
avrdude: reading input file "0b11110101"
avrdude: writing efuse (1 bytes):
Writing | ################################################## | 100% 0.00s
avrdude: 1 bytes of efuse written
avrdude: verifying efuse memory against 0b11110101:
avrdude: load data efuse data from input file 0b11110101:
avrdude: input file 0b11110101 contains 1 bytes
avrdude: reading on-chip efuse data:
Reading | ################################################## | 100% 0.00s
avrdude: verifying ...
avrdude: 1 bytes of efuse verified
avrdude: reading input file "0b11010110"
avrdude: writing hfuse (1 bytes):
Writing | ################################################## | 100% 0.00s
avrdude: 1 bytes of hfuse written
avrdude: verifying hfuse memory against 0b11010110:
avrdude: load data hfuse data from input file 0b11010110:
avrdude: input file 0b11010110 contains 1 bytes
avrdude: reading on-chip hfuse data:
Reading | ################################################## | 100% 0.00s
avrdude: verifying ...
avrdude: 1 bytes of hfuse verified
avrdude: reading input file "0b11111111"
avrdude: writing lfuse (1 bytes):
Writing | ################################################## | 100% 0.00s
avrdude: 1 bytes of lfuse written
avrdude: verifying lfuse memory against 0b11111111:
avrdude: load data lfuse data from input file 0b11111111:
avrdude: input file 0b11111111 contains 1 bytes
avrdude: reading on-chip lfuse data:
Reading | ################################################## | 100% 0.00s
avrdude: verifying ...
avrdude: 1 bytes of lfuse verified
avrdude done. Thank you.
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 : usbasp
Description : USBasp, http://www.fischl.de/usbasp/
avrdude: set SCK frequency to 16000 Hz
avrdude: warning: cannot set sck period. please check for usbasp firmware update.
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.00s
avrdude: Device signature = 0x1e9516 (probably m328pb)
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: set SCK frequency to 16000 Hz
avrdude: warning: cannot set sck period. please check for usbasp firmware update.
avrdude: reading input file "C:\Users\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.3/bootloaders/optiboot_flash/bootloaders/atmega328pb/16000000L/optiboot_flash_atmega328pb_UART0_115200_16000000L_B5.hex"
avrdude: writing flash (32768 bytes):
Writing | ################################################## | 100% -0.00s
avrdude: 32768 bytes of flash written
avrdude: verifying flash memory against C:\Users\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.3/bootloaders/optiboot_flash/bootloaders/atmega328pb/16000000L/optiboot_flash_atmega328pb_UART0_115200_16000000L_B5.hex:
avrdude: load data flash data from input file C:\Users\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.3/bootloaders/optiboot_flash/bootloaders/atmega328pb/16000000L/optiboot_flash_atmega328pb_UART0_115200_16000000L_B5.hex:
avrdude: input file C:\Users\dekip\AppData\Local\Arduino15\packages\MiniCore\hardware\avr\2.1.3/bootloaders/optiboot_flash/bootloaders/atmega328pb/16000000L/optiboot_flash_atmega328pb_UART0_115200_16000000L_B5.hex contains 32768 bytes
avrdude: reading on-chip flash data:
Reading | ################################################## | 100% 0.00s
avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x7e00
0xff != 0x01
avrdude: verification error; content mismatch
avrdude done. Thank you.
Error while burning bootloader.
Hi everybody! I'd like to hook up to the topic.
Here's my setup that works just normal for burning bootloader by using MiniCore Atmega328, but with internal crystal: Internal 8MHz clock, BOD disabled, EEPROM retained, LTO disabled, 328PB, Bootloader UART0;
Goal is to obviously get it to work with external 16MHz crystal which doesn't in my case too. I've tried with normal 2pin crystal package and 22pF as well as 6.8pF caps. Doesn't work. Now I'm planning to try with different crystal type and load caps.
Any other suggestions?
Hi Mylossh
I had similar problems with mega328pb using resonators. Mega328p worked fine for years, switch to m328pb (same PCB), and the problems started. Problems while programming with AVRISP MKII and stability while operating. I had some contacts with Microchip tech support but with no luck. Dead end. Eventually the problem was solved by redesigning the PCB and use a oscillator on XTAL1 pin. No more issues. HTH
Joaquim
Eventually the problem was solved by redesigning the PCB and use a oscillator on XTAL1 pin.
Yes, using a dedicated clock connected to the XTAL1 pin would definitely solve the issue. Or create your own crystal driver like shown below (where IC2A is optional):
I'm using this exact circuit to drive crystals when using ATtiny13 or ATmega4809, where neither of them can drive a crystal but supports a clock input signal.
Can you put some light on this 74hc04 IC? From what I can see it is Schmitt Trigger. According to the datasheet https://www.diodes.com/assets/Datasheets/74HC04.pdf, it seems to have 3 channels. In this schematic you provided, you use two of the ICs and only one channel from both. Besides, You use pins 2 and 4, and for input and output, and it should be, say 1A and 1Y (pins 1 and 2). Correct me where I am wrong.
Don't look too much on the actual pins. I've been using a 74HC1G04 in a SOT353 package.
The 74HC04 does not have a Schmitt triggered input, the 74HC14 does.
https://assets.nexperia.com/documents/data-sheet/74HC_HCT1G04.pdf This one? That makes things clear.
What could be used as a replacement? This is not available at my place. :( I can order it abroad, though.
I use this (or similar):
https://eu.mouser.com/ProductDetail/Epson-Timing/SG5032CCN-16000000M-HJGA3?qs=sGAEpiMZZMvjAcTDbo5QTpwxKcangighf21RCgxfPBQ%3D
You can use any 74XX04, It's a generic, non-Schmitt-triggered inverter. if there are unused inverters in a package, you can just wire the inputs low or high, and leave the output unconected.
Hello guys! Since I have around 20pcs of 328 in PB version, I've decided to design a small dev board for it, so that I can try if it accepts bootloader with oscillator instead of crystal as you suggested. Could anyone possibly check schematic from PDF that is attached? I'm not sure if everything is connected as it should be. If I understood the Datasheet, oscillator output should be connected to PB6/XTAL1? Thanks in advance! AtMega328PB dev.pdf
The schematic looks alright to me. I would however recommend you to add a diode from the RST line to VCC, to prevent voltage doubling when the DTR signal does its thing, which can make the chip enter high voltage parallel programming mode.
@ITstreet1 did you resolve the issue in the end?
If not, as a test, you can try Adafruits Arduino as ISP sketch instead. It works exactly like the "original" one, when used with a 16 MHz UNO, it outputs a stable, 8 MHz clock on digital pin 9. If you connect this pin directly to the XTAL1 pin on your 328PB, it should work.
Hello my dear friend, your mini core really saved me a lot and I was able to solve the boot loading, but I have an issue. I interfaced it with and lcd and sometimes it just keeps restarting and shows random letters and sometimes it just restarts repeatedly. I’m using Atmega328pb
In any case, MiniCore optiboot_flash bootloader works fine with ATmega328PB. So this issue can be closed as the issue may be more HW related.
Gotta open this one.
Finally, I find time to make this one work. Board is here, and everything is soldered. I successfully burned the bootloader with Nano. Tried to upload a simple Blink sketch over the USB (UART CH340C) but get this error:
Arduino: 1.8.19 (Windows 10), Board: "ATmega328, Yes (UART0), EEPROM retained, 328PB, BOD 2.7V, LTO disabled, External 16 MHz"
Sketch uses 1232 bytes (3%) of program storage space. Maximum is 32256 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x84
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x84
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x84
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x84
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x84
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x84
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x84
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x84
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x84
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x84
Problem uploading to board. See https://support.arduino.cc/hc/en-us/sections/360003198300 for suggestions.
This report would have more information with "Show verbose output during compilation" option enabled in File -> Preferences.
What is interesting, I can upload a sketch using Nano as a programmer over an SPI. I double-checked all solder joints, and everything is fine. I also tried your "diode fix" from the above post, but no luck.
Any suggestion?