LM7805 voltage drop when attach load
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Although nothing getting hot, maybe only the transformer, by a little, there was a flipped IC. Now the thing is really hot is my head. I think Eagle have trolled me. The atmega was horizontally mirrored. The schematic is correct, but the board doesn't match. I'll figure what happened after solve my problem. Thx you all... Like always, it's the small rocks that make you fall. –  Pedro Quadros 1 hour ago
Some how my Atmega was on top board instead of on bottom. Probably I messed with it when arranging the components and didn't realize it