Custom ATMEGA328P board... should I use Arduino Uno in the IDE to upload?

Hi all,

I made a custom atmega328p board (5V, 16Mhz) and successfully burnt the arduino optiboot bootloader using atmel ice. Now for uploading a sketch... I am using this ftdi usb breakout: USB Serial Light Adapter - Atmega8U2 (Arduino Compatible)-DFRobot

In the Arduino IDE, should I just select Arduino Uno? Or should I select something like the pro mini and specify the processor as ATMEGA328P 5V, 16Mhz ?

Thank you and sorry if this is a silly question..

Use the Uno. Connect the FTDI RX to TX and TX to RX. Connect DTR to reset through a 0.1uF cap to do the autoreset.

Thank you and sorry if this is a silly question..

Don't be sorry, I found the whole thing kind of confusing at the start, too.

Don't forget Gnd too. And 10K pullup resistor on reset; the 0.1uF/10K in combinations create the reset pulse when DTR goes low.

I bootload all my 328P/16MHz projects as an Uno, so I don't have to keep track of what chip is bootloaded as what.

A schematic of the connection:

328 ftdi.jpg

328 ftdi.jpg


Thanks guys, RESET is already broken out to my FTDI pins on my board as shown through the 0.1uF cap so that it can go to DTR on the FTDI adapter, so it should work!

Out of curiosity, if I did select pro mini and selected the 328P @ 16Mhz what would have happened? I have read that if you don't select the right frequency, ie. 8Mhz instead then your delays and timing would be off because the compiler would not compile for the correct frequency. But if selected 16Mhz accordingly, is there anything inherently different about a pro mini @ 16MHz than an UNO @ 16MHz that would cause issues?

Or take the chip out your uno and plug the new 328 into that and program as a normal UNO , saves messing with wires !

Can’t remove the chip as it is an SMD version on a custom PCB