# Previously used AT328 cannot get Arduino Mega 2560 as ISP **URL:** \ **Category:** 3rd Party Boards\ **Created:** [October 24, 2025, 8:18pm UTC](https://forum.arduino.cc/t/previously-used-at328-cannot-get-arduino-mega-2560-as-isp/1410519 "2025-10-24T20:18:04Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![jcb\_24](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jcb_24/32/1017822_2.png) [@jcb\_24](https://forum.arduino.cc/u/jcb_24)\ **Post date:** [October 24, 2025, 8:18pm UTC](https://forum.arduino.cc/t/previously-used-at328-cannot-get-arduino-mega-2560-as-isp/1410519/1 "2025-10-24T20:18:04Z")
Hello! So I was using my Arduino Mega 2560 as an ISP and successfully flashing my code onto my AT328PU chip and then I dropped my breadboards ☹ and my Arduino stopped working as an ISP. I re-assembled my project and probably foolishly, I re-uploaded the Arduino as ISP sketch where SCK is 52, MISO 50, and MOSI 51 and this worked. However when I went to flash to AT328 it no longer worked. I tried re-burning the bootloader but haven’t been able to do this. **Here is my setup right now** (same as previously): AT328 pin 1 → Mega2560 RESET AT328 pin 7, 8 — .1uF cap across — pin 7 to +5V, pin 8 to GND AT328 pin 20, 22 — .1uF cap across — pin 20 +5V, pin 22 to GND AT328 pin 9, 10 — 16MHz crystal across — pin 9 to 22pF to GND, pin 10 to 22pF to GND AT328 pin 17 — Mega2560 pin 51 AT328 pin 18 — Mega2560 pin 50 AT328 pin 19 — Mega2560 pin 52 Mega2560 pin 10 to 10uF cap to GND Mega2560 pin 9 to resistor to LED (track ISP is running via heartbeat) All +5V and GNDs are rails common to Mega2560 GND and +5V outputs This is exact set up I had before. I see the LED heartbeat flashing indicating that MEga2560 is running ISP script. **Then I try to flash a script I get this output** (note that the first part of the output is just from my personal bat script that I use for flashing. It was working previously so not the culprit of the problem): ```arduino Cleaning preivous build... rm -f piezo-0.elf piezo-0.hex Building Project... avr-gcc -mmcu=atmega328p -DF_CPU=16000000UL -Os -o piezo-0.elf piezo-0.c avr-objcopy -O ihex -R .eeprom piezo-0.elf piezo-0.hex avrdude: Version 6.3-20190619 Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/ Copyright (c) 2007-2014 Joerg Wunsch System wide configuration file is "C:\Users\jcbls\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17\etc\avrdude.conf" Using Port : COM3 Using Programmer : stk500v1 Overriding Baud Rate : 19200 AVR Part : ATmega328P 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 efuse 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 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% 0.09s avrdude: Device signature = 0x000000 (retrying) Reading | ################################################## | 100% 0.05s avrdude: Device signature = 0x020000 avrdude: Expected signature for ATmega328P is 1E 95 0F Double check chip, or use -F to override this check. avrdude done. Thank you. Done! Press any key to continue . . . ``` **Here is the output when I try to upload a new bootloader (Tools→board–\>Uno, Programmer → Arduino as ISP):** ```arduino "C:\Users\jcbls\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17/bin/avrdude" "-CC:\Users\jcbls\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17/etc/avrdude.conf" -v -patmega328p -cstk500v1 -PCOM3 -b19200 -e -Ulock:w:0x3F:m -Uefuse:w:0xFD:m -Uhfuse:w:0xDE:m -Ulfuse:w:0xFF:m avrdude: Version 6.3-20190619Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/Copyright (c) 2007-2014 Joerg Wunsch System wide configuration file is "C:\Users\jcbls\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17/etc/avrdude.conf" Using Port : COM3 Using Programmer : stk500v1 Overriding Baud Rate : 19200 AVR Part : ATmega328P 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 efuse 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 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% 0.02s avrdude: Device signature = 0x000000 (retrying) Reading | ################################################## | 100% 0.03s avrdude: Device signature = 0x000000 (retrying) Reading | ################################################## | 100% 0.02s avrdude: Device signature = 0x000000avrdude: Yikes! Invalid device signature.Double check connections and try again, or use -F to overridethis check. avrdude done. Thank you. Failed chip erase: uploading error: exit status 1 ``` What should I be doing to re-establish the connection betwen mega2560 and at328? Again the at328 has been in use **it is not fresh!!!** so I imagine the steps are a bit different? Thank you for your help in advance! ---
**Author:** ![Deva\_Rishi](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/deva_rishi/32/227254_2.png) [@Deva\_Rishi](https://forum.arduino.cc/u/Deva_Rishi)\ **Post date:** [October 24, 2025, 8:34pm UTC](https://forum.arduino.cc/t/previously-used-at328-cannot-get-arduino-mega-2560-as-isp/1410519/2 "2025-10-24T20:34:46Z")
> [@jcb\_24](#): > > `avrdude: Device signature = 0x000000 (retrying)` Is usually a sign of a bad connection. A breadboard is not a reliable setup. First of all check all connections with a DMM. Atmega328p pin to Mega pin. You will probably find something that is not connected (or wrongly) Ehen you succeed create a soldered version of your uploader. ---
**Author:** ![b707](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/b707/32/854321_2.png) [@b707](https://forum.arduino.cc/u/b707)\ **Post date:** [October 24, 2025, 8:37pm UTC](https://forum.arduino.cc/t/previously-used-at328-cannot-get-arduino-mega-2560-as-isp/1410519/3 "2025-10-24T20:37:54Z")
> [@jcb\_24](#): > > AT328 pin 1 → Mega2560 RESET Your ISP board (i.e Mega) should controls the Reset pin of the target board - on AT328. So the connection above must be inverted - you need connect a digital pin of Mega to Reset on AT328. ---
**Author:** ![jcb\_24](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jcb_24/32/1017822_2.png) [@jcb\_24](https://forum.arduino.cc/u/jcb_24)\ **Post date:** [October 24, 2025, 8:44pm UTC](https://forum.arduino.cc/t/previously-used-at328-cannot-get-arduino-mega-2560-as-isp/1410519/4 "2025-10-24T20:44:03Z")
Yep! that was silly of me lol – thank you for catching that ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [April 22, 2026, 8:44pm UTC](https://forum.arduino.cc/t/previously-used-at328-cannot-get-arduino-mega-2560-as-isp/1410519/5 "2026-04-22T20:44:19Z")
Closed on April 22, 2026, 8:44pm UTC This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.