Burning eFuse without USB exposed?

[lllius]

I recently made a board using the ESP-WROOM-02D module, and assumed I could just program this with JTAG via my JLINK EDU. I didn't route the USB pins at all, since I have absolutely no need for CDC or other USB functionality. I thought it was dumb to put a USB Micro connector if I'm not going to use it, so I put a tag-connect (little pogo pin cable) footprint for the JTAG signals and I hacked up a little protoboard to connect this to my JLINK.

Upon receiving and assembling my board, I'm finding that I have to burn the DIS_USB_JTAG fuse in order to use an external adapter. But in order to do this I'm pretty sure I need to connect to the USB serial interface. https://docs.espressif.com/projects/esp ... -jtag.html

Is it possible to burn the eFuse in my board's current configuration (no USB)?

[ESP_Sprite]

Do you still have access to U0TXD and U0RXD? If so, you can also use those to program the chip and/or burn fuses.

[lllius]

Oh great! I didn't realize you could do that. I was able to use an external FTDI board to burn the fuse. Thanks