Arduino autoreset problem

hi guys

Im new in this forum, im writing because im getting problems with arduino into a board that the company i work for has designed. The problem is: the arduino is doing auto reset, we have a conection with "no" 5V+ to the reset pin, and the reset is doing it. I have tried putting 5V+ with a serial 10k resistence to the reset pin and stills doing auto reset. What do you think? could be a feeding problem? i have tried many times and still dont have the fail. We have a code that just debug heartbeats without any communication taking place. We have set the regular connection with quartz glass and capacitors.

Thanks and i hope you can help me!

Pablo :slightly_frowning_face:

pablozang: The problem is: the arduino is doing auto reset

I suppose you like the feature, that the Arduino powers up and starts via auto reset, so auto reset on its own is a very nice feature.

You forgot to tell when and under what circumstances the reset happens, that is bothering you.

You will have to provide a lot more information before anybody can help you.

Which Arduino are you talking about?

What happens when?

What is attached to the device and how?

OK, we are using ATMEGA328P-PU. im going to explain a little more specific. We can see the arduino starts up with a led connected to a GPIO pin that we set flickering in the code. So the problem is arduino starts working and the led starts flickering, suddenly the led stops it and we check with debug option that have made a restart, this happens sometimes few seconds after starting or few minutes after starting, so its kind weird this, we have tried with some arduinos making sure that are not damaged. We are almost sure that the problem is not the code. We are feeding with 5V+ on VCC . On the image we have the reset pin with a serial push button to GND. I have tried looking for some schematics on internet putting 5V+ with a 10k serial resistence connceted to a reset pin (pin 1 ) but still does not work i mean, arduino does the same, auto reset. Its clear what i wrote? if not just give a feedback.

Thanks very much

I am still not clear on this. 1. You are not using any arduino board? 2. You have something connected to the reset pin? 3. What if you disconnect the reset pin? 4. Your LED on the GPIO pin does have a resistor in series? 5. You can measure, with a voltmeter the 5v, and it is stable? 6. Is this on a a breadboard, or a PCB that you made? 7. It is always good to see the sketch, can you provide that (inside the code tags )?

If you pulled up your reset, then it won’t get reset unless your code has error. So no code posted, I see.

Hi Jack,

  1. We just set the program into the microntroller with the arduino 1 board
  2. We have our own board designed and we have a 10k serial resistence connected to GND and to pin 1 (RESET)
  3. The only way to disconnect it is cut the track to reset
  4. the GPIO signal goes directly to a transistor to amplify the current and turn the led on
  5. The source VCC is stable 5.32V+
  6. Yes it is me made this board with eagle soft cad
  7. Do you have eagle cad?

Have had any problem similar to this?

Thanks a lot…


this is the simple code we are just trying

Do all your boards behave like that?

Did you use the watchdog feature on the misbehaving board in the past?

". the GPIO signal goes directly to a transistor to amplify the current and turn the led on"

This could cause such a problem. You should place a resistor between the GPIO and the transistor base. I would guess around 500 - 1000 ohm.

7. No, I don't have Eagle cad.

  1. We have our own board designed and we have a 10k serial resistence connected to GND and to pin 1 (RESET)

Resistor needs to pull the pin up to VCC, not down to Gnd. The chip is reset when the pin is low.

@CrossRoads, good catch. I am embarrassed that I did not catch that when I read it. Thanks.

Hi guys,

i have made a change. I changed the board source for an external source and i measured the consumption with both sources. The board we have designed has his own source, with the board source the two arduinos are consuming 130mA and still doing reset and there is no 5V+ to reset pin (Pin 1) i mean the reset to GND. With an external source arduinos are consuming 60mA with 5V+ to the reset pin (pin1) and work perfectly. Its weird, can make the reset pin consuming much more from both Arduinos? and this issue they make reset ?

What do you suggest that i have to do? i really need help.



We have already been here (twice). But once more. Please provide the answers. Else, I will give up.

  1. Is the reset connected to a resistor, that is connected to +5v ?
  2. Is there a resistor between the GPIO pin and the base of the transistor? what value?

hi jack

  1. Yes the reset is connected with a serial resistence of 10k with a source of 5.32V+
  2. The resistence at the base of the transistor has value of 3.3k

sorry for being late. What do you suggest to me to do?

Thanks a lot.


There are several things that can cause a reset. You may want to check each (I may not have a complete iist).

  1. Reset pin, going low ( or floating low ). Use a volt meter on the pin.
  2. Software reset.
  3. Power dropping below the required level. Take off all the heavy loads, and use a voltmeter.

Have you tested this on a bread board? You may want to.