Hi !
I have just bought a Atmega328. I connected it up and did burn a 8Mhz bootloader on it without problem. I disconnected USB, and rip off all cables, connected it up without crytsal and capacitors.
When I plug the 5V line the UNO is shutting down. I have also tried with external power (300mA), still shutting down.
I hope someone can help me.
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Thanks for your answer, I have attached a picture.
The Uno stops, disconnect from USB, and all LEDS are turned off. As soon as I remove the 5V line it starts up and connecting again.
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I have checked several times... and I havent turned it since I uploaded the bootloader. Now there is a picture there, it was to big, but now I have corrected it
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Having the uno shut down probably means that something is shorting 5v to gnd.
Xian:
Hi !I have just bought a Atmega328. I connected it up and did burn a 8Mhz bootloader on it without problem. I disconnected USB, and rip off all cables, connected it up without crytsal and capacitors.
When I plug the 5V line the UNO is shutting down. I have also tried with external power (300mA), still shutting down.I hope someone can help me.
What bootloader did you burn?
How do you know that it is "shutting down"? Such a choice of words is not precise, and carries a connotation that the chip is operating for a time, and then turns off. Is that what happens? Or maybe the controller never starts to begin with, and you're confusing "not turning on" with "shutting down".
I don't know your skill level. Instead of using vague terms, describe precisely what you did to the chip, what circuit you are putting it in, and what symptoms you are seeing. Do not make assumptions about causes or operations that you cannot see yourself or measure with an instrument.
I suspect that you burned a Pro Mini bootloader (or something similar) onto the chip, thinking that "8 MHz" inherently refers to the internal 8 MHz oscillator. This is false. There is only one board in the official list that ever used the internal oscillator. I can't remember what it is, I think it was a Lilypad. The Pro Mini uses an external resonator, same as an Uno. Most 8 MHz boards still require an external crystal or resonator, they just have an 8 MHz one fitted instead of the normal 16 MHz.
I dont know what happens, but now it work better. The same setup. The boards didnt shut down, but problem with uploading. Have to play a bit with it...
Something happens to the uno, I cant upload anything to it.... I have tried from mac and pc. Both says the programmer is out of sync...
