I try to make a custom board with atmega328pu and an FT232RLN to program with usb.
I successfully set the new atmega328p chip, but after that, when I want to upload a new program (like blink), the TX led of the FT232RLN blinks, but not the RX. It seems atmega328p not responding.
I get this error on the arduino IDE :
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x3c
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x3c
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x3c```
I already tried to test USB communication (with shunting RX and TX) and I successfully received back what I send via the serial monitor.
Also, when I program the atmega chip on a genuine arduino uno and I replace the chip on my custom board, the program work (blink)
So for me, there is a link problem between the atmega chip and the FT232RLN or something I need to set on the arduino IDE to be able to upload ? (I use AVRISP mkll programmer)
Bellow my schematic.
https://ibb.co/JzKSNxC
https://ibb.co/vYn8NW7
Thanks for your help.
So I upload a simple sketch on the 328 with the arduino genuine pcb (sending 'A char' to the serial port every 2 second).
After putting the 328 in the custom PCB, I see that the ft 232 RX led blinks every 2 second, so I suppose that the problem come from the ft232 communication...
thank you @jim-p problem solved with two things :
1 - Before "burn bootloader", select arduino nano board (Arduino as ISP for the uno master)
2- I sold the D3 diode in the wrong way, so after correct it, everything goes fine !