Arduino IL Drive Sim read good write bad

[J-F Garnier]

(04-27-2023 07:04 AM)ThomasF Wrote:  

(04-27-2023 06:51 AM)J-F Garnier Wrote:  Connecting both the ESP and the USB on the same serial lines creates a electrical conflict on the Tx line (towards the PIL-Box IC) - the strongest wins.
I would recommend to insert a e.g. 10k resistor in the Tx line from the USB, so the ESP will take precedence softly, and if not present the USB will still operate.

I never thought of connecting both at the same time, but it might be worth adding some protection in case of!

A short clarification: the conflict will exist even if no USB cable is attached, since the USB module is powered from your ESP cable and so will attempt to drive the TX line at its idle level.

J-F