Can I fix portA and portC ?

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#1
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Guys,

Can I fix PortA and PortC on ATMEGA128 ?
It seems to be broken, I can not test them with blinking LED, other ports are fine, PortB,D,E,F,G...

Any ideas, or it's not possible to fix it ?
thanks

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Could it be the M103C fuse? But on the whole PORTC and PORTA should b no different to any other port.

I cannot help noticing when I look at "alternate port functions" in the datasheet that PORTA is AD0..7 and PORTC is AA8..A15. Could it be that you have enabled the external memory interface?

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Did you perhaps enable external memory?

[Edit: Cliff was a bit faster.]

Jörg Wunsch

Please don't send me PMs, use email if you want to approach me personally.

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Have you seen smoke come from your mega128?

Which dev board are you using ?
How did you connect your LED ?

If you concentrated on one subject at a time, you would get on far better !

David.

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I wrote a little port a,b,d,c output readback test that sets the ddr to outputs, write 0xff, sets to inputs, reads back the pin, repeat for 0x00, repeat for ea port.

Imagecraft compiler user

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Could it be the M103C fuse?
I double check it, I disable already this fuse,

Could it be that you have enabled the external memory interface?
No I didn't enabled the external memory,

Could it be because of input voltage ?
I'm trying with 19V input for the voltage divider

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Have you seen smoke come from your mega128?

Which dev board are you using ?
How did you connect your LED ?

No I haven't seen smoke come from my mega128,
I'm using my own customized development board, create schematic and PCB myself.
LED is connected to PD3 and PD4

May be the chip is broken already....

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hmmm a great business idea, a chip repair centre.....

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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Okay, it's time for me replacing the chip isn't it, or I'll move the PORT to a working port...another way, just develope a new board...but may be I'll break all the port first before I develope a new one...hehehe

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In your video(s) there is a fairly sophisticated dev board with headers, SDCard, jumpers etc.

If you designed and built this all by yourself, you should be able to breeze through any minor software problems.

You will also understand about SPI, JTAG, fuses, external memory interfaces, ...

David.

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Some test, so far, it can be read, written and the fuse is correct

Any other possibilities ?

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David, I think I break the PORT...
:)

The broken PORT are always High, even I asked them to change to Low.....

I'm sure the code is right, I used it for many times and it's only asking those ports changing from Low to High....

PC4 still alive, it's blinking but other bits on PortC are broken, and PORTA is broken no blink at all....I guess it's time for me moving to other ports....do you reckon ?

Last Edited: Fri. Sep 20, 2013 - 10:15 PM
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Does 2000W heat gun from bunning have enough heat for desoldering it ? it's controllable to 500W, but I can't see the temperature....and I don't have a square nozzle for it, may be I'll roll the dice, it's broken anyway ;)

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I fix it already with heat gun and replace ATMEGA128 chip, now it's fine...

Thanks for helping guys

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I'm surprised you didn't try the suggestion I offered of writing FF and 00 to the PORTs and reading the PINs back. That tells you that the outputs and the inputs are working in each port. You must be a hw guy. You went for the hw fix first. I'm a sw guy. I'll do ANYTHING to keep from desoldering a TQFP.

Imagecraft compiler user

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I tried already your method PORT by PORT sending 00 and FF, PORT A and C failed, and I tested with LCD on PORT F and PORT D, failed too...so I decided, I need to say goodbye to the chip, now it's sticking into my saddle bag as a decoration hehe..