burn bootloader atmega 2560 but floating

hello,

i have already burn bootloader to minimum system atmgea 2560 but when i use led blink the voltage only 1.7 volt, what i must to do to make 4.98 volt??

i burn bootloader with usb asp and slow sck is on and burn bootloader no error

thanks :smiley:

Can you explain what it going on ?
When you set an output pin high, it is only 1.7V ?
Can you try to measure the voltage without the led.

Do you use a resistor with that led ?

I burn bootloader sir and the led very fade when i use basic led blinking and i tested it using avometer and the voltage stable 1.7volt sir (steady)
:frowning: the burnbootloader done without error

If you set the pin as output and high (no blinking) and without the led, is the pin 5V ?
Do you use a resistor with that led ?

yes i use resistor 330 and the supply is 5volt from my downloader all i have tested sir:D

Did you remember to set pin as output in setup()? (or some time before you try to turn on the LED).

pinMode(pin,OUTPUT);

If you don't do that, the pin is not considered an output, and can barely supply any current - so the voltage drops to 1.7v (the point at which the current going through the LED matches what the MCU is supplying), and hence the LED barely glows.

of course i already give the basic setup the I/O

all supply correct 4.98 volt to the IC but when i use basic BLINK from example it didnt work

so what i suppose to do?