Current after activating Serial

Using Arduino Microcontrollers
#1

Hi All,

i am using Arduino MiniPro (At328)

With empty sketch is current flow is 10mA at 12V (PS connected to RAW pin)

When is in setup section activated serial communication using commmand :
Serial.begin(9600)

then the current flow is 70mA at 6V (PS connected to RAW pin)
if i tried use 8V the At328 is heating up. On 9V is hot in 5s.
Current is at about 100mA for chip.

Arduino is running standalone

Has anybody idea why is the chip so hot?

#2

Where are you connecting your input voltage to?

#3

Power Suply is connected to RAW pin.

#4

Put power on the raw pin and measure the voltage on the 5V line... What is it?

#5

What is connected to the serial pins?

#6

The 328 should not be getting hot in use. Something is wrong. My guess is that something else in setup() is the problem, and you've got a pin trying to source or sink waaaay too much current. Check for output pins that setup sets to go high that are shorted (or nearly shorted) to ground, and ones that are set to go low shorted to +5.

Have you gone through setup() removing lines to find out for certain what line it starts drawing 70ma at?

And yeah, make sure the 5v is at 5v.

#7

HI all,

Steps how to reproduce it :

  1. Disconnect everything from arduino..let it stand alone.
  2. connect USB ASP
  3. Upload sketch "A"/"B"
  4. Disconnect USB ASP
  5. connect (6V) + to RAW pin and - to GND pin
  6. check current on you PS.
    The arduino current is depended on the program "A" or "B".

Sketch "A" for current 70mA :
void setup()
{
Serial.begin(9600);
}

void loop()
{
}

Sketch "B" for current UP TO 10mA :
void setup()
{
}

void loop()
{
}

#8

Current solved....RXD and TXD weresoldered to Ground.

#9

How on earth did that happen? How did you manage to upload a sketch?

#10

two words: usb... asp...

op did make that clear. and actually did phrase it as two words.

#11