Hello, I am currently making a little simple project, in which I am using a 328P-AU on a self-designed PCB from JLCPCB and components from lcsc. You probably know what I mean.
I just started to try to burn the bootloader and failed even after triplechecking every single detail. Then I started to apprehend that my own "Arduino" might be the problem. Therefore I looked at the waveform of the two crystal oscillator pins of a "normal" Arduino Uno with my oscilloscope (DS1054Z, unlocked completly). I know that the capacitance of the probe messes up the desired oscillation but I saw something going on there. When I looked at the two pins on my own design, I saw absolutely nothing. The pins are completly dead, hanging arround at GND.
Paul_KD7HB:
I hope you tried substituting one of the other crystals you bought and did any of them work?
Paul
Sort of. I removed the one from the link and replaced it with a big crystal from an Arduino Uno but the same result appears. Now I think the crystal probably is not the problem. I do not really want to solder on another one from the link because I have only one left. I am pretty sure I did not mess up anything with the soldering. Does anybody see a mistake in the schematic?
Check that neither of the crystal pins are shorted to ground or eachother. Particularly with small smd caps on boards assembled by hand, its easy to get a solder bridge under the cap.
Also, what error do you get whem burning bootloader, with verbose output when uploading enabled? Sig of 0x000000 is symptom of chip set to use crystal whem crystal isnt oscillating or isnt present.
A factory fresh chip runs with a 1 MHz r/c clock that allows the ISP interface to function. If the ISP interface is wrong and avrdude was not able to set the fuses in the chip, the oscillator will not be running, it’s still running the r/c clock.
Since you didn’t post a full schematic it is impossible to tell you if it is correct.
hallolo:
Hello, I am currently making a little simple project, in which I am using a 328P-AU on a self-designed PCB from JLCPCB and components from lcsc. You probably know what I mean.
Can you post an image of your PCB pattern please?
Is it single or double sided?
How close do you have the crystal to the crystal pins of the controller?
How close do you have the two caps and their gnd connections to the crystal?
Ok. I actually found a short to GND on pin 7 (XTAL1). But this occured only after removing the original crystal, the original crystal was soldered just fine. But I assume shorting this pin to GND can permanently damage the 328? Because then, I can cancel this whole try anyways since I only ordered one 328 and I would order it at lcsc again anyways and this would open up the possibility to redesign the whole schematic and pcb. I think I will reorganize/redesign everything in the next days and will probably consult this forum again before ordering with the new whole schematic.
Sorry for wasting your time just because I designed and assembled this project too unpremeditated.
Could you describe how you are trying to burn the bootloader, and what type of programmer you are using?
I always wonder, especially with a surface mount chip, why is there no ISP header on the board, or at least a convenient pad layout for connecting the programmer.
hallolo:
Hello, I am currently making a little simple project, in which I am using a 328P-AU on a self-designed PCB from JLCPCB and components from lcsc. You probably know what I mean.
I will just mention after all the to-and-fro, this sounds like a classic exercise in creative head-banging.
A "Pro Mini" board has all the components you need - albeit with a regulator and pilot light you are unlikely to need - already assembled and inexpensive.
