I have plenty ESP32 modules, but all they require a USB cable - always the type I don't happen to have by hand. Also sometimes would be convenient to plug an ESP32 directly to a USB power supply without a cable. This project is about wiring an ESP32 Wroom module to a widely available and cheap ESP8266 USB breakout board. This DM-102 board also has a UART and supports flashing, no auto boot mode like many ESP modules but there is a reset button and a switch for GPIO0 so flashing is convenient enough.
I have always a pair in my EDC (Every Day carry) box if I happen to need to try communicating between ESP32s or so.
DM-102 USB breakout board for ESP8266 (without the ESP8266 module)
Solder a cm or two of tinned copper wire to the TxD, RxD, GPIO0 and Reset (optionally GPIO13 for some added rigidity) pads of the DM-102
Solder similar pieces of coated wrapping wire to Vcc and Gnd pads of the DM-102 (I used black for ground and red for Vcc)
Place couple of layers of thick double sided adhesive tape on the DM-102, where the ESP32 is going to be placed at
Place the ESP32 on the adhesive, pins aligned roughly as in the picture above
Solder the wires to ESP32, peel the coated wires, cut all short after soldering
Do continuity test between DM-102 pads and ESP32 pins, and between adjacent ESP32 pins to find unintended shortcuts
Plug into a computer, keep finger on the ESP and power regulator on the other side to notice if they are heating abnormally (anything you'd feel in less than 30 secs or so)
Turn Switch into "PROG", click the button, try flashing something from Arduino IDE or whatever, turn switch to "UART", click again, review results (serial console probably in this point)
If planning to use other GPIOs, it's easier to solder on the DM-102 before attaching the ESP module but can be done later. I strongly recommend soldering any required extra GPIOs also to the board as you won't get very robust connections directly to the ESP's crown "pins". A male / female header or DuPont connector can be hot glued to the other side for IO.