Maybe this could help :

Also, some DC-DC chips are specially designed for that, such Linear LTC4267 :
http://cds.linear.com/docs/en/datasheet/4267fc.pdf

Do you mind explaining why I should not connect the USB UART's 3.3V to ESP32 though?

The USB-Serial is self powered from the USB line. Therefore it's 3.3V is an output, and your ESP32 has already it own power supply.
Shorting 2 power supplies together could cause damage.

1st of December which is only a couple of weeks away

You probably means "couple of days" ...

What is the question exactly ?
Because all states are present in gpio_intr_status, you simply needs to verify each bits as needed.

BTW, folks and @rudi, using "switch/case" with numeric values for each interrupt is not a good practice. If both interrupts come at the same time, your code won't handle any, since gpio_intr_status will be set to 393216. You should use bitmask as "if (gpio_intr_status & 0x02000) {}" and "if (gpio_in...

Maybe we can use the ROM function in the mean time :

int uart_rx_one_char(uint8_t *ch);

+1 or even +2
Thanks, ESP_Sprite !

The ESP32 isn't in production yet, therefore you can't purchase some. Those guys who have one became part of Beta campaign, limited to 200 modules, back in Nov 2015. I've tried to become part of those, they even ask me to provide my phone number, but they actually ran out of modules to quickly and I...

Congrats to me-no-dev !!!

Yes, in other words, the ONLY time the pin is acting as an output is when the SDA/SCL needs to be bring to LOW, in any other states, the pins should be back to Input mode, leaving the pullups doing their job, also allowing the Slaves to do such things like "clock stretching". (Unfortunately, I can't...