user68988: so , just bought some pre-bootloaded ATmega328(p/pu) to which I need to upload sketches on a breadboard using uno TX and RX pin as FTDI
Here is what I am to do.

I connected Uno GND and Reset .

Arduino Tx to Standalone Atmega Tx

Arduino Rx to Standalone Atmegaa Rx

Connected Crystal , capacitor to standalone pin 9, 10 (XTAL) then grounded it with 2 coupling capacitor.

Standalone vcc to arduino 5v
Standalone GND to Uno GND


Is it possible to do what I need to or i need to buy some USB to TTL devices from the Amazon again?
Thanks for your precious time...

user2881: That sounds about right.
The only problem is that normally, when a serial connection is created, the Arduino's reset pin is briefly pulled LOW. You would have to do that manually on the ATMega on your breadboard. I can be a bit tricky to get the timing right.
There is no easy way to get this signal to your breadboard ATMega, while keeping the reset pin on the UNO's ATMega LOW.
Removing the ATMega from the UNO board would work.

user69739: https://youtu.be/EoHD0m3uUhA. Ig this should do it. There are many more tutorials on YouTube to achieve this.

68988: <p>so , just bought some pre-bootloaded ATmega328(p/pu) to which I need to upload sketches on a breadboard using uno TX and RX pin as FTDI</p>
<p>Here is what I am to do.</p>
<ol>
<li><p>I connected Uno GND and Reset .</p>
</li>
<li><p>Arduino Tx to Standalone Atmega Tx</p>
</li>
<li><p>Arduino Rx to Standalone Atmegaa Rx</p>
</li>
<li><p>Connected Crystal , capacitor to standalone pin 9, 10 (XTAL) then grounded it with 2 coupling capacitor.</p>
</li>
<li><p>Standalone vcc to arduino 5v
Standalone GND to Uno GND</p>
</li>
</ol>
<p>Is it possible to do what I need to or i need to buy some USB to TTL devices from the Amazon again?</p>
<p>Thanks for your precious time...</p>
 2881: <p>That sounds about right.</p>
<p>The only problem is that normally, when a serial connection is created, the Arduino's reset pin is briefly pulled LOW. You would have to do that manually on the ATMega on your breadboard. I can be a bit tricky to get the timing right.</p>
<p>There is no easy way to get this signal to your breadboard ATMega, while keeping the reset pin on the UNO's ATMega LOW.</p>
<p>Removing the ATMega from the UNO board would work.</p>
 69739: <p><a href="https://youtu.be/EoHD0m3uUhA" rel="nofollow noreferrer">https://youtu.be/EoHD0m3uUhA</a>. Ig this should do it. There are many more tutorials on YouTube to achieve this.</p>
