After soldering my atmega328 tqfp smd chip on my PCB, i can see that my chip is working with a standard blink sketch uploaded earlier The problem is that i cannot upload a new sketch using FTDI adapter in my new board, and this is below the schematic:

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Is there some tricky stuff to do before trying to upload any sketch ?

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    \$\begingroup\$ Is the crystal frequency really 81.620GHz? Are you really powering the circuit with 4.2V? Does LED DS1 really connect directly to SCK without a series resistor? What color is the LED? What (if anything) is connected to pin 29? What are the fuse settings in the MCU? \$\endgroup\$ – Bruce Abbott Sep 22 '19 at 22:13
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    \$\begingroup\$ I would guess that your baud rate is off because of the odd crystal value. AFAIK you need 8.000MHz or 16.000MHz (with appropriate board selection in the Arduino IDE) to get sketches uploaded. Note that Bruce's concerns are all accurate, these are all serious issues and using the LED without current limiting resistor could destroy the MCU. \$\endgroup\$ – Dean Franks Sep 22 '19 at 22:35
  • \$\begingroup\$ The crystal and the atmega chip are took from an arduino pro mini. The thing is that the blink steckh is working with the led, the only issue is that even if i connect my tx rx correctly with my ftdi and using Arduino IDE, my skech cannot be uploaded, and i powered the board with a 3.3v source \$\endgroup\$ – Mehdi Sep 23 '19 at 7:12
  • \$\begingroup\$ What exact output messages does avrdude report when attempting to load the firmware? Also I am wondering whether the brownout detector flags need to be changed for the different power supply voltage. I frequently use both 5V Arduino uno and 3.3V Arduino pro mini, and the flags are programmed to different values. Check the data sheet. Also don’t leave reset and spi-cs pins floating, this can put the part in a state where it expects to receive new firmware over the spi bus (instead of the bootloader). Both reset and spi-cs need resistor pull-up to logic high. \$\endgroup\$ – MarkU Sep 23 '19 at 8:13

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