Problem uploading sketch on DIY board

Hello everyone,

I have designed a sensor that uses the ATMega 328p as its µC since I wanted to just be easily test my code.
After building and testing the sensor I combined it all on a pcb and basically copied the the design for the Arduino Pro Mini.
Now while trying to upload a sketch (via programmer) or the bootloader I just get the error that the device ID ist invalid. avrdude ist just reading 0x000000 as the deviceID what made me first think I had some errors in my wiring however I checked all wires, used shorter or longer, etc.
Then I tried using an bench power supply instead of the battery that I used. That did not help as well.

I have attached the part of the ATMega of the schematic.

If anyone has an idea I would really appreciate it.

Edit: I just saw I messed the schematic up a bit while rearranging it. Of course the gnd of the decoupling caps is not connected to the pin 19. Please ignore that.

0x000000 signature indicates wiring error, or crystal (or external clock) selected, but no crystal or external clock is present.

Well I double checked that several times.The 8Mhz crystal is there, the solder connection is good and the caps are to ground are also in spec.

I have also traces out all wires and made sure that they are all connected with the multimeter.

I have tried using other arduinos as programmers and an AVR ISP mk2.

Ok it was just a bad luck. Two boards were faulty. The third and fourth worked flawless. I do not understand why but well at least it works.

The first two places I would look are:

  • Solder shorts
  • Via's not connected to other side.


"cold" solder joints (where there is solder on one or both parts but no connection - i've seen bad solder joints that wouldn't work, but would test OK with a multimeter, because when you pressed the multimeter onto the pin, it would push the pins together and then they'd make contact.) and solder bridges (two adjacent pads connected) are the most common. Unconnected vias are rare these days on professionally made circuit boards, even cheap ones. One thing I've seen many times is that small SMD capacitors can have a solder bridge under the part (for that error, maybe one of the loading caps on the crystal.