Cool, I didn't know it. Actually, there's so much stuff on the internet that it's practically impossible that someone hasn't had the same idea several times before. It's a shame the manufacturer of this module didn't place IO9 testpad in a location with easy access for soldering.

Marco

Hi,

My solution was to use an old ESP32 module as a USB serial programmer and an 8-pin DIP clip on the edge of the board. For IO9, you can solder a wire and connect it directly to the programmer's IO0, or momentarily touch a test probe with your hand during the programming phase in your preferred ...