Why is flashing the Xiao C6 over UART different from the Espressif C6-DevKitM-1?

[MiloEnzo]

@emill185

I need to flash a custom device with a ESP32 C6 that doesn’t have a USB header, but does have a UART broken out. Flashing that wasn’t working, so I stepped back to dev boards to ensure my toolchain and procedure was correct.

When I hook the RX and TX pins of an ESP Prog board to the RX and TX pins of an ESP32 C6 Xiao, I can flash it exactly as I expect.

However, when I hook the same board up to an Espessif C6-DevKitM-1 or my custom board, it just hangs and fails. I’ve confirmed that I can see serial logs through the FTDI chip, so I’ve got the TX and RX pins hooked up correctly.

Does anyone know what Seeed did differently with the Game Room Download? Am I missing an option in MenuConfig or something?

Are there any hardware flow control settings (e.g., RTS/CTS) that the Xiao uses but the Espressif DevKit doesn’t?