ESP32 Remote Debugging

Example for ESP32 remote debug with ESP-Prog adapter and PlatformIO

Hardware

• ESP32 (no USB2Serial adapter or separate power supply needed)
• ESP-Prog JTAG Debug & Program Downloader (12,80€ + 3,24€ shipping) https://s.click.aliexpress.com/e/BejpuNBE
• Dupont cables female-(whatever your ESP32 needs) or similar (5-10)
  • 1 for ground
  • 4 for JTAG (TDI, TDO, TCK and TMS)
  • 1 optional for Power if ESP32 should be powered via the ESP-Prog
  • 1 optional for serial RX if you want to receive boot messages from the ESP32 via the ESP-Prog
  • 1 optional for serial TX if you want to send data to the ESP32 via the ESP-Prog
  • 2 optional for Reset and IO0 if you want to automatically control boot mode for flashing
• USB cable (ESP-Prog micro port to whatever fits into your computer)

Software

Minimalist

I did not test this

• openOCD (maybe special Espressif version)
• gdb from Tensilica toolchain
• https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/jtag-debugging/index.html :)

IDE

• VS Code
• PlatformIO for VS Code

PlatformIO Project Config

add this to your platformio.ini:

debug_tool = esp-prog
debug_init_break = tbreak setup

; Not needed for remote debugging, but to make sure platformio does not pick the wrong port, now that we have more than one...
monitor_port = {yourProgPortName}
monitor_speed = 115200

;left here for experiments...
;upload_port = {yourProgPortName}
;upload_protocol = esp-prog

{yourProgPortName} could be /dev/ttyUSB2 or COM5 or similar (the lower of the 2 ports Esp-Prog exposes)

Quirks

• On Windows you need some USB driver assignment tool and drivers (not tested, let Andreas Spiess explain it to you: https://youtu.be/psMqilqlrRQ)
• Newer linux distros might not preinstall the old libcurses5 library. On opensuse 15.1 I had to install it:

sudo zypper install libncurses5

• Remember: pin RX goes to TX and TX to RX crossed, but TDI and TDO are not crossed like the other pins

Recommended

If you want Linux to assign fixed port names for your adapter, create a file /etc/udev/rules.d/98-Dual-RS232-HS.rules

SUBSYSTEMS=="usb", ATTRS{interface}=="Dual RS232-HS", KERNELS=="*:1.0", MODE:="0660", GROUP:="dialout", SYMLINK+="ttyUSB_jtag"
SUBSYSTEMS=="usb", ATTRS{interface}=="Dual RS232-HS", KERNELS=="*:1.1", MODE:="0660", GROUP:="dialout", SYMLINK+="ttyUSB_prog"

Then execute

sudo udevadm control --reload-rules
sudo udevadm trigger

Once you plug in the Esp-Prog, you will see /dev/ttyUSB_prog and /dev/ttyUSB_jtag devices with full access for group dialout now. The *_jtag device is not really needed, because the driver finds it anyways (at least if you only have one attached at a time, like me).

Finally make sure you are a member of group dialout:

sudo usermod -aG dialout $USER

you may need to logout and login again to see the change with command id

Go!

• Attach your ESP32 to ESP-Prog and that via USB to your computer.
• Open your project in VS Code and press Ctr-Shift-D and/or F5

Project should build, upload, start and break at the setup() routine.