Problem with uploading the sketch for my DIY Arduino uno

Other Hardware General Electronics
1

I just finished building my first DIY UNO, the problem is that I can't even upload anything onto the ATMEGA328. It noticed the programmer is not responding error and I don't know why.

I used CP2102 Serial to UART converter for uploading and I've connected all 4 required pin which are

RX(CP2102) ---> TX(ATMEGA328)
TX(CP2102) ---> RX(ATMEGA328)
VCC and GND are used to power the board.

I measured the voltage in many important points like VCC and GND of uC and I got the same amount of voltage which varies between 4.9V-5.1V which is the voltage that is used to operate the uC.

My board is very simple, I used regulated 5V from CP2102. When I try uploading the sketch, and I pressed reset button which has already been tested. Nothing happened and there was stk500_recv error shown.

2

connected all 4 required pin

The main snag is that you require 5 pins not 4.
The extra one is the DTR pin through a 0.1uF capacitor to the reset pin.

Have you got the drivers for that chip installed? Are you seeing it in the tools menu?
Are you on a Mac? The DTR does not work correctly on that system.

3

First of all, thank you very much Grumpy_Mike

I am on Mac. So I can use CP2102 without installing the driver. But please explain about the DTR pin? I used to use only 4 pins to upload on the UNO I purchased from Ebay and also Pro Mini and it worked. All i had to do is just pressing the reset button.

4

chattana_j:
All I had to do is just pressing the reset button.

Entirely correct, but you have to know when to press it, and more correctly, when to release it.

Specifically (and of course the chip you are using has a bootloader on it, doesn't it?), you press reset briefly when you see the "Uploading..." message in the blue bar on the IDE.

chattana_j:
I used to use only 4 pins to upload on the UNO I purchased from Ebay and also Pro Mini and it worked.

Fair enough on the Pro Mini, but why - or how - would you use "4 pins to upload on the UNO" which you plug directly in to the USB?

OK, so if you have used the Pro Mini, you presumably do know the reset timing, but what about the bootloader? Did you try swapping the 328 into the UNO?