[SOLVED] CP2102 with DTR pin - ERROR 0x00 not in sync


I recently bought CP2102 from aliexpress and I can't upload sketches to arduino. I burned bootloader and it will program normally if it is on arduino uno board, but I can't put it on home made board and upload.

The board that I have made is Nanino. My connection to the board is

TX0 - RX RX0 - TX VCC - VCC GND - GND DTR - RESET via 0.1 uf cap

I tried connecting with TX0 - TX and RX0 - RX, pressing reset button before upload appeared, but still no response from programmer. How should I configure IDE and how can I test programmer to make sure it's working properly. I have one Mega and Uno at home, so I can test it with thoose to if needed. Thank you very much

have a nice day :)

Take out the capacitor.

I did remove capacitor, but no change.

Test the adapter alone with RX jumpered to TX, see if it echoes what you type on the serial monitor.

Do you have the 10k pull-up on the rest pin? You must have a capacitor on your board between the DTR connection and the reset, do not be confused about this requirement. On the other hand, you must not have any other capacitor on the reset pin.

Does the board you have made function correctly with the chip you programmed on the UNO board, demonstrating that the crystal (or resonator) is functioning correctly? Is the crystal or resonator of the correct frequency?

Have you studied Nick’s tutorial?

Okay, I got it working. The CP2102 module works without problem. I don’t know what the problem was, probably badly made PCB.

So the setup with this particiular board was. The module from original post,
(CP2102) ------ (Arduino)
GND ------------ GND
VCC ------------ VCC

DTR ------------ RESET, put ceramic capacitor (100nF/0.1uF) in series so DTR >----||-----< RESET

TX ------------- RX (PIN2)
RX ------------- TX (PIN3)

In device manager I selected baud rate 115200 and COM11 port. In Arduino IDE settings are:
Board: UNO
Com port: COM11
Programmer: AVR ISP

I hope this helps

Thank you for all the help :smiley: