[gh02t]

They have a built in serial bootloader. Most dev boards don't need anything, they come with a USB-to-serial adapter. Some of the new ones even have the USB part integrated on chip.

If you use a bare module then you need a basic 3.3V serial adapter and maybe a jumper wire to ground pin 0 to enter programming mode.

You can also do stuff with JTAG, which will let you use a debugger, but that's not mandatory. Espressif sells a dirt cheap one. I think maybe you can use your jlink for that with some fiddling but I'm not certain.

[seba_dos1]

> Some of the new ones even have the USB part integrated on chip.

Worth noting that this includes JTAG over USB.

[gh02t]

I haven't tried the newer ones with USB support since I have a literal stack of older ESP32s to get through for projects, how's support for JTAG/debugging over USB in the common environments like ESP-IDF/Arduino/Platformio/etc? If it's not a hassle to get it set up then I might have to pick one up to develop on.

[seba_dos1]

I'm simply launching openocd and gdb and it works well. But the only way I've ever used Arduino was via arduino-cli, so I may not be the best person to ask :P