Hello All,
I have been fighting with a DIY design Atmega 328 -Au SMD chip. I can program it with the Atmega programmer now problem. However anytime I try to update the sketch with USB to serial adaptor it will never upload. I have tried everything I can think of. But I hook put my atmega programmer it works every time.
Is there anything else about the SMD version why I could be having these maybe timing programs.
I do want to stress the mkII programmer works every time when hooked up.
I have even build a home made Uno DIY board and the same USB to serial interface works and uploaded sketch's no problem.
This is the first time I have used the SMD version guys. Is there anything I am missing about the SMD version? Help I am stuck.
There is no other difference between -AU and -PU only package, first is SMD and second is PDIP. But there is a difference between ATmega328 and ATmega328P. P means pico power. They have different signature. Be sure that you have selected correct MCU during upload. Maybe the problem is in this difference. In that case you have to edit the boards.txt file. Arduino has defined ATmega328P in boards.txt.
The -PU and -AU have different physical pin #s, the -AU has 2 VCC pins and I think 3 GND pins? All must be hooked up. Port assignments to software names is still the same. The IDE doesn't know about the physical package type, -PU, -AU, or -MU.
And the two extra ADC inputs that evildave pointed out.
A schematic (and possibly a picture if it wasn't build by a fab house) of the board in question would help.
I had a 328p-au board recently that I could bootload (SPI) but not program (FTDI), and it turned out to be because I never connected Voltage to the 3 voltage pins (doh!), just the bypass cap. Enough power leaked through on the SPI signals to power it enough to bootload apparently.