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Topic: Invalid Device Signature, was working before (Read 1 time) previous topic - next topic

HamzaY

#15
May 25, 2019, 06:57 am Last Edit: May 25, 2019, 06:58 am by HamzaY
Good improvement on the posts, thanks.   It would be good to improve the schematic a bit, so we understand the corrections made by the black lines.  
Two ic grounds are connected to ground.


Black lines are used to represent a connection or a wire. VCC and AVCC both are connected to 5v.


Also setup is a little messy so if you need anymore assist understanding feel free to ask.


dmjlambert

I recommend working on cleaning up the schematic to make it very clear, and make corrections so it represents what you actually have on your completed board.   

Are you using atmega328p-au or atmega328pb-au IC on your board?   They are different, and I am concerned that you mentioned atmega328p above but schematic says atmega328pb.   

Are the atmega328p pins 16 and 23 connected together and going to MISO?
And are pins 29 and 1 connected together and going to your reset pullup?
There should be 2 VCC, 1 AVCC, and 3 grounds, but the schematic does not show all those.
I'm afraid you need decoupling capacitors, that may be the root of the problem, but I don't know.




HamzaY

I recommend working on cleaning up the schematic to make it very clear, and make corrections so it represents what you actually have on your completed board.   

Are you using atmega328p-au or atmega328pb-au IC on your board?   They are different, and I am concerned that you mentioned atmega328p above but schematic says atmega328pb.   

Are the atmega328p pins 16 and 23 connected together and going to MISO?
And are pins 29 and 1 connected together and going to your reset pullup?
There should be 2 VCC, 1 AVCC, and 3 grounds, but the schematic does not show all those.
I'm afraid you need decoupling capacitors, that may be the root of the problem, but I don't know.




i am using atmega328p-au. I understand both are different and that is why i had made changes to pcb as shown in schematics. Rest of pinout is same. And yes pin 29 to 1, 16 to 23 and 17 to 24 is connected to account for different variant of ic. Also decoupling capacitor is also connected between gnd and 5v. (i think wiring is not the problem as if it was it wouldnt have worked the first time)


I also been searching other posts for possible solution what i understand is during unsuccessful uploads,fuses were somehow changed resulting in bricking of 328p.

Also is there any way to over ride the signature verification, i know it wont upload but wanna do it just to understand the problem better.

Also thanks for your help too, i know you are trying your best and i really appreciate it.

Coding Badly


HamzaY

#19
May 27, 2019, 11:25 pm Last Edit: May 27, 2019, 11:42 pm by HamzaY
Solved!!!
The issue was that after few time successfully uploading code using 'upload using programmer' for some reason the atmega 328p got bricked (happened twice with two different atmega 328p). So solution was that to change atmega 328p ic and burn boot loader after that instead of using isp programming to upload your code use FTDI programmer .

Thanks Everybody for help.

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