I've made a home-made Arduino based on this video. The problem is that I can't upload anything, it doesn't react, only the LED double blinks in every second. What does that mean? How to fix it? Thanks.

Update: photo

  • 1
    This is surely impossible to answer without seeing what you did. Presumably you did something different from what is in the video, what that is, is impossible to say. I suggest posting a very clear photograph, at the very least.
    – Nick Gammon
    Mar 3, 2016 at 20:49
  • Thanks for the quick reply - I've just provided one. Hope that helps. Thanks :)
    – haxpanel
    Mar 3, 2016 at 21:05
  • Did you bought atmega chip with bootloader already on it?
    – brtiberio
    Mar 3, 2016 at 21:11
  • I guess so - at least according to the Ebay seller.
    – haxpanel
    Mar 3, 2016 at 21:13

1 Answer 1


It's a reasonably clear photo (another couple would help) however I do see at least one major problem. Pin 8 (and pin 22) are Ground, but I don't see any wires running to that. Also the 22 pF (or similar) capacitors connected to the crystal should have their other sides grounded.

I suggest you look at my page Breadboard Arduino which has clear photos and wiring guides. In particular:

Minimal Arduino

Notice the ground wire, and how the capacitors are connected.

I suggest you double-check all wiring, and make sure it is very similar to this:

Atmega328P wiring

  • I've just checked it but the 22s are already grounded to pin 8 as that is a ground. I updated that area anyway according to your photo but having the same issue. I've built this entire stuff for 3 times but getting the same result. :(
    – haxpanel
    Mar 3, 2016 at 21:25
  • 1
    Yes, but pin 8 should have a ground wire. You shouldn't rely on it being grounded through the chip. Also the capacitor in series with reset looks a lot larger than 0.1 µF.
    – Nick Gammon
    Mar 3, 2016 at 21:58
  • Ohh I see, mine is a 100uF one. I mixed up with the 100nF. The smallest I have now is a 1uF. I wish I could just quickly "download" one ...
    – haxpanel
    Mar 3, 2016 at 23:51
  • 3D printer? And a bit of aluminium foil? Just remove the wire leading to the capacitor. When the upload starts briefly ground it to reset the processor (a quick tap) and then un-ground it.
    – Nick Gammon
    Mar 4, 2016 at 0:09
  • I haven't got any 3D printer but an oven and a hair dryer. Am I still good?
    – haxpanel
    Mar 4, 2016 at 11:05

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.