JTAG Debug with WROVER-KIT Example not working

[Greg-R]

So the JTAG clock speed is changed by editing a file included with OpenOCD:

share/openocd/scripts/board/esp32-wrover.cfg

Open this file and look for this line:

adapter_khz 20000

For example, to change to 10MHz clock:

adapter_khz 10000

Save and close the file. Note that there is a different file if your board has the WROOM module:

esp-wroom-32.cfg

Now, trying again with the clock set to 5MHz, I had no better luck than before. In fact, there were even more strange errors.
Then, I removed the JTAG jumpers and tried using the FTDI cable, which works with a regular WROOM dev board.
This seemed to be even worse, and it did not appear to communicate with OpenOCD successfully.
Changing the clock frequency seemed to make things behave differently.

The FTDI cable with the WROOM dev board is solid. So for now, I am going to assume the WROVER kit board I have here has a problem.
I will be getting another one, so if that one works, that will be the conclusion.

Continuing on with the story of the FTDI cable, here is the manual:

[urlhttp://www.ftdichip.com/Support/Documents/Data ... _CABLE.PDF][/url]

This cable is available from Amazon (in the USA):

https://www.amazon.com/gp/product/B00HK ... UTF8&psc=1

You will need to connect ground and the 4 JTAG wires to your development board.
The connections are listed here:

http://esp-idf.readthedocs.io/en/latest ... -jtag.html

Here is the command to start the JTAG connection:

bin/openocd -s share/openocd/scripts -f interface/ftdi/um232h.cfg -f board/esp-wroom-32.cfg

The JTAG cable is using /dev/ttyUSB0. The board is connected to /dev/ttyUSB1 (change in menuconfig).
As noted above, I had to decrease the JTAG frequency in the file esp-wroom-32.cfg from 20000 to 10000.

Note that in this case the interface file is um233h.cfg. This is the configuration for the FTDI cable.

Regards,
Greg