Nano to ATMEGA328P on the PCB - Is this Schematic correct?

Hello again.

On my first thread I had asked about transferring codes from Nano to ATMEGA328 (here)

Later when I searched the Internet, I read that because my Nano uses SMD version (unlike some of the Uno that use DIP) for ATMEGA, I cannot remove it and replace with the ATMEGA328P and proceed. I need something called FTDI and it is not going to get delivered until September 5th, 2020 (darn these delays coz of the present prevailing conditions) :frowning:

As I wait, I decided to read some more, and realized that I would need some add-ons and changes when I replace the Nano on the PCB with a ATMEGA328P -

  1. Power Source
  2. Switch
  3. Crystal -16MHz
    4. 220pf Capacitors
  4. 22pF capacitors thanks @Budvar10 for pointing out my typo.

Maybe I am missing something as well.

I made a Schematic on Fritzing (I love Internet just because there are so many great tools available today and I am still trying to learn it), back in my days, I would have used a pen and paper.

On the Left is the regular Arduino Nano version - which works good.

On the Right is the proposed version using ATMEGA 328P - Sorry, I am still learning everything and at my age, I know I am slower - and I could not find a way to get 22pF instead of 22uF on the capacitors.

I would really appreciate if some from the community can have a look and let me know if this will be okay or I need to add or remove some components.

Oh, let me also mention that I never studied electronics as a course, though today, I want to, as this Arduino stuff has made me really interested.

EDIT: I could not add the image in the text. I am not sure why. Hence I have attached it as a PNG.

Here on the web is schematics for Nano. Use this. Did you see?

Capacitors for oscillator are not 220pF nor 22uF. They are 22pF. Reset pin have to be pulled up via 10kOhm.
Also, you should read datasheet, how to power MCU. All VCC and GND have to be connected....

sid-74:
I need something called FTDI and it is not going to get delivered until September 5th, 2020 (darn these delays coz of the present prevailing conditions) :frowning:

Although it's a little bit more complicated, you can use your Nano in place of the FTDI. Just let us know if you want instructions for that.

sid-74:
EDIT: I could not add the image in the text. I am not sure why. Hence I have attached it as a PNG.

Instructions for how to do that are here:

I made a Schematic on Fritzing

Better to use pencil and paper. Fritzing is a complete waste of time for everyone. For one, the pinout shown for the ATmega328 is not correct, so the schematic can never be correct.

Comments as in the previous posts, plus you need to connect power to Vcc as well as AVcc. You need 0.1 uF decoupling capacitors between Vcc and GND in a couple of places, close to the chip. See below right.

jremington:
For one, the pinout shown for the ATmega328 is not correct, so the schematic can never be correct.

What's the error in the pinout?

Sorry, it looks OK after all. I looked at the 32 pin package pinout, not the 28 pin.

Budvar10:
Here on the web is schematics for Nano. Use this. Did you see?

Capacitors for oscillator are not 220pF nor 22uF. They are 22pF. Reset pin have to be pulled up via 10kOhm.
Also, you should read datasheet, how to power MCU. All VCC and GND have to be connected…

Yes, I did see the schematics and here is what I interpreted -

  1. The first one at the top left - is the pin out structure

2a. The first on the second row (titled Arduino) - Now that this has been posted in the context of my question, I understand it better - it is to be used when I am powering the Nano without the USB.
2b. The one on the right (on the second row) - is when using the USB to serial (FTDI?) method.

  1. The 3 images at the bottom rows are confusing and I probably dont know much here.

As for the capacitors, I wrongly typed 220 instead of 22pF. On my free version of Fritzing, I could not find them and neither could change their capacity. Also, there was no ATMEGA328P or even some others. Probably I use a free version and maybe that is why it is limited or maybe any other reason.

I have to read about the Datasheets etc that you mention.

I am grateful to you for pointing out the flaws in my approach and even letting me know what the process should be. I never studied electronics as a subject though I did copy and used circuits during my school days. And now, I got some time to make something. And many recommended using Arduino - so I signed up a couple of YouTube Channels and started out. As such, you can see, I lack the correct directions. Thanks for being here and helping me.

jremington:
Better to use pencil and paper. Fritzing is a complete waste of time for everyone. For one, the pinout shown for the ATmega328 is not correct, so the schematic can never be correct.

Comments as in the previous posts, plus you need to connect power to Vcc as well as AVcc. You need 0.1 uF decoupling capacitors between Vcc and GND in a couple of places, close to the chip. See below right.

I do understand you. I use a free version of Fritzing, and somehow, it did not have ATMEGA328P - when I searched the Internet, I found that the ATMEGA328 can be replaced with ATMEGA328P as they are the same family (but in some cases it is not wise to replace ATMEGA328P with ATMEGA328). Hence I used the one that I could find.

Thank you for the schematics. On the image (the one on the right) - I see that the PIN Out for ATMEGA 328 is marked differently - I mean, there are 10 pins on the left side and the others are all on the right. I find something similar in on some other schematics as well. Is it just for representation purposes or the ICs are different? (again, a very naive question, I guess).

And that C3 - 0.1uF - that is the one used in isolation?

Thank you for taking your time to reply. It will help me for sure.

pert:
Although it's a little bit more complicated, you can use your Nano in place of the FTDI. Just let us know if you want instructions for that.

I would surely be interested but at the stage that I am in, I assume it will only add to complications - reason being I am very very new to all of this. Surely say after a couple of months.

pert:
Instructions for how to do that are here:
http://forum.arduino.cc/index.php?topic=364156.0

Thanks. What I could gather was this -

  1. Inline images are possible if the image is online already.
  2. Either use Google Drive or others (if the image is elsewhere on the web) or Upload the image (from local computer) as attachment, open it in new tab, copy that link and then use the Insert Image button on the editor.

I believe that is correct. I have noted down the steps.

sid-74:
Thanks. What I could gather was this -

  1. Inline images are possible if the image is online already.

Correct.

sid-74:
2. Either use Google Drive or others (if the image is elsewhere on the web)

That will work sometimes. Other times it won't, either because the file/image hosting service actively prevents this "hotlinking" due to it wasting their bandwidth, or because it's difficult to get the right form of link to the image.

The other problem with hosting the image outside the forum is that the external image tends to disappear over time. In addition to being a place to help people directly, this forum also serves as a huge collection of knowledge. So when we answer your question, we may also the same question for many others over the years who find that forum thread in a Google search. That thread will usually lose its informational value if the image being discussed disappears.

For this reason, attaching the image to the post itself is superior, since this keeps the post and image in the same place.

sid-74:
Is it just for representation purposes

Just different stylistic choices by the person creating the schematic symbol.

You’ll find that professional level IC schematic symbols will almost always be in the form similar to that shown in the schematic jremington posted. A schematic is only intended to show the electrical connections of a circuit, not to be a representation of the layout of the circuit. For this reason, it makes more sense to group the pins in a logical form that is convenient for use on a schematic (as done on the symbol on jremington’s schematic), rather than laying the pins out the same as the physical part (as done on the fritzing symbol you used).

sid-74:
And that C3 - 0.1uF - that is the one used in isolation?

It’s for decoupling.