How to change device signature in avrdude config

Projects Programming
1

Hi Guys
Need help please I am trying to upload a hex file to an atmega48 and I am getting a message telling me the device signature is wrong the device signature that is being returned is for an atmega8 and not for the atmega48 .
I am using an Arduino Uno to upload the hex file , before posting this topic I tried googling for an answer one of the answers was to change the signature in the avrdude.conf file .
I have have tried opening the file but I am getting no where I also tried turning off auto reset by connecting a 10uF capacitor across reset and ground on the Uno this made no difference
Thanks oldguyjn

2

The device signature is hard-coded into the chip. If avrdude says you have an atmega8, you HAVE an atmega8. Likely a counterfeit chip, or one that has been re-marked and re-sold as a 48. Hardly an uncommon problem these days.

3

I suppose it’s improper to ask that you ensure you’ve
selected ATMEGA48 as the target device in your programmer/uploader.

Sorry, but I have to ask.

4

Thanks Guys
Ray with regards the chip I will not name the supplier other than its a very large supplierr in the UK and generally you are not allowed to purchase from individually but normally need a company account and is a reputible company lastchancename nothin is improper when it comes to my coding skill
Below is a screenshot of what what is displayd in the command prompt by the way I have also replacing m48 with m48p but this makes no difference
Once again guys thanks fo taking the time to read and reply to my post
oldguyjn

c:\Program Files (x86)\Arduino\hardware\tools\avr\bin>avrdude -C ../etc/avrdude.conf -c avrisp -P COM4 -b 19200 -p m48 -U flash:w:"K:\usbasp.atmega48.2009-02-28.hex":i

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.03s

avrdude: Device signature = 0x1e920a (probably m48p)
avrdude: Expected signature for ATmega48 is 1E 92 05
         Double check chip, or use -F to override this check.

avrdude done.  Thank you.
5

Well, if you REALLY believe the chip is an atmega8, the error message tells you how to ignore the signature check...

6

Thanks for the prompt reply Ray
If I was to use -F could I ruin the chip
oldguyin

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It looks like your "ATmega48" is actually an ATmega48P (like the Arduino UNO has an ATmega328P and not an ATmega328). It looks like you are trying to flash it with usbasp firmware. It should work if you change the "-p m48" part of the command to "-p m48p".

8

John
Thanks for the reply I decided before I tried -p m48p to uninstall avrdude and do a fresh install and what I found was that I had more than one version of avrdude on my computer I have now ensured that as of now avrdude is not on my computer and I am going to carry out a fresh install tomorrow and follow your advice
Thanks again oldguyin

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johnwasser
Thanks for advice all working and again thanks to all for taking time to reply to my topic
oldguyjn

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