If you see this error while trying to use OpenOCD with JTAG on ESP32:
$ sudo esp32-openocd -c "set ESP_RTOS none" -f board/esp32-wrover-kit-3.3v.cfg
Open On-Chip Debugger v0.10.0-esp32-20210401-48-g041b08f6-dirty (2022-10-15-18:05)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
none
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : ftdi: if you experience problems at higher adapter clocks, try the command "ftdi_tdo_sample_edge falling"
Info : clock speed 20000 kHz
Error: JTAG scan chain interrogation failed: all ones
Error: Check JTAG interface, timings, target power, etc.
Error: Trying to use configured scan chain anyway...
Error: esp32.cpu0: IR capture error; saw 0x1f not 0x01
Warn : Bypassing JTAG setup events due to errors
Info : Listening on port 3333 for gdb connections
Info : accepting 'gdb' connection on tcp/3333
Error: Target not examined yet
Error executing event gdb-attach on target esp32.cpu0:And after including the suggested “ftdi_tdo_sample_edge falling”
$ sudo esp32-openocd -c "set ESP_RTOS none" -f board/esp32-wrover-kit-3.3v.cfg
Open On-Chip Debugger v0.10.0-esp32-20210401-48-g041b08f6-dirty (2022-10-15-18:05)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
none
ftdi samples TDO on falling edge of TCK
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : clock speed 20000 kHz
Error: JTAG scan chain interrogation failed: all ones
Error: Check JTAG interface, timings, target power, etc.
Error: Trying to use configured scan chain anyway...
Error: esp32.cpu0: IR capture error; saw 0x1f not 0x01
Warn : Bypassing JTAG setup events due to errors
Info : Listening on port 3333 for gdb connections
Info : accepting 'gdb' connection on tcp/3333
Error: Target not examined yet
Error executing event gdb-attach on target esp32.cpu0:This error is easy to fix: you are connecting something external to GPIO pins 12-15 or you are enabling these pins in your code.