Hi.
I'm trying to make an original Arduino using this. However, similar works on the Internet have various circuits and I am confused.
I made it using ATMEGA328P-AU, but I wired it in the same way as ATMEGA328P-PU, is that okay?
The circuit diagram is shown below. I want you to check...
Did it work ?
You don’t have pins 5 and 6 and 21 connected on the 32 pin package shown.
5, 6 and 21 are omitted because they are GND, VCC and GND respectively.
That’s exactly the reason why they need to be connected !
oh...
I'm connecting VCC and GND at different locations. Do I need to connect to all VCC and GND pins?
Yes you do.
I didn't know that! thank you!!
You might want to put a capacitor from Reset\ to ground. This will serve as a crude reset on power up.
BTW you are using the 32 pin version which is not easily breadboarded, Is you ultimate goal a PCB?
The AVR has its own reset-on-powerup, and the cap to ground will interfere with Arduino-style auto-reset functionality that you might want to add eventually.
Thanks didn't know. Is it enabled by default?
That is correct! My goal is a PCB!
Is your goal a project or trying to make a very small board?
All my projects have been to make something I could not purchase, or with features that were unavailable in offered boards.
My current board is a SD card + RTC + battery + plugin for 1.3" OLED. All the eBay, Adafruit, spark fun SD boards have a Chip select flaw that allows only one SPI on the bus. My board fixes that.
Clearly your projects are your own, I'm just suggesting a different point of view.
John
1 Like
Which package is that board designed for?
The built-in POR circuit only provides a flag to see if it has occurred and does not have a setting register or fuse, so I think it is always active and cannot be disabled.
Thank you, I never realized that feature was built in 
That's why I like these forums, while trying to help others I often learn new things and get new ideas.
My goal is to make a very small board.
My robot needed a small arduino.
This Arduino will fit on a 20mm x 30mm board.
finally i finished making my circuit. By your advice, i could improve my circuit! please check my circuit at last please.
Could you not use one of these?
There are a number of others available on the internet.
Proposed Thank you!
However, I wanted to make an Arduino with pin arrangements that match the robot, so I would like to avoid purchasing ready-made products this time.
Understand, just wanted to be sure you knew about the alternatives.
Another suggestion:
Soldering the 32Pin SMD is not an easy feat but is possible with a soldering iron but it takes some practice. So you might consider using one of the very small boards, making an adapter to your robot pinout.
1 Like