On further investigation, the drive strength setting does work on the ESP32, but gpio_dump_io_configuration does not reflect the updated values (always returns 2 even if value is different). Testing on the ESP32-C3, gpio_dump_io_configuration does detect the changed value, so perhaps this is some ...

To eliminate ESPHome as a variable, I installed ESP-IDF 5.4.1 and wrote a simple program that changes the drive strength:

#include "driver/gpio.h"

void app_main(void)
{
gpio_num_t gpio_num = GPIO_NUM_4;


gpio_dump_io_configuration(stdout, (1ULL << GPIO_NUM_4));

// Configure the GPIO as ...

Based on some posts here (e.g. https://esp32.com/viewtopic.php?f=2&t=2027), I expected that the GPIO drive strength current limits should adjust the GPIO output impedance, which could be used to optimize signal/noise on digital IO lines. To confirm this, I measured the output impedance by hooking an ...