Flash Download Tool: Can't Download

[munulu]

I have a board from TTGO that has an ESP and a CH9102 for serial communication. In installed the Windows driver (USB-Enhanced-SERIAL CH9102) and everything looks fine as far as I can tell. For good measure I rebooted the computer. I then defined 4 binaries that I want to download. I set the SPI speed to 40MHz and SPI mode to DOUT (as per instructions). I selected the correct COM port (verified by checking the driver name and also unplugging and plugging the board back in while observing which port disappears). But then when I click on start I get a popup saying:

"2-sync fail. Tips: Please refer to the chip datasheet and confirm that strapping pins's status is correct."

In the DOS window it says:

"[2023-02-28 22:17:26,375][ESP8266Loader_spi[1]][espDownloader.py][line:566][ERROR]: IOError: the serial port should probably be removed
[2023-02-28 22:17:26,376][ESP8266Loader_spi[1]][espDownloader.py][line:759][ERROR]: ESP32 Chip sync error esp_sync_blocking."

What could be wrong? Note that this is a board that others are using with the same settings in flash download tool and they didn't experience this issue.

[nchase]

I'm facing the same issue on some custom boards. Any updates on this?

[nchase]

We eliminated the issue by switching to esptool (https://github.com/espressif/esptool/releases).