Delayed connection of periphs to ESP32 Strapping pins with MUX?

Hello again,

I was wondering how I could use a multiplexor to delay connection of the strapping pins 0, 2, 4, 5, 12, and 15 to after boot. How would I connect it?

Matt

You mean like this?

As done with a bi-directional switch?

Or do you mean at boot, whiles setup runs you configures those pins to a open, pull up or pull down state?

The pins 0, 2, 4, 5, 12, and 15 on an ESP32.

I have found pin 0 and 4 to be trouble less you might want to consider your pin use as described.

GPIO_5 and GPIO_15 are the ESP32 natural SPI cs pins. I have the least issues with the ESP32 using the HSPI bus, which naturally uses pin 15. GPIO_5 is the natural pin select for the VSPI buss.

GPIO_2 is the on board LED for the ESP32, non WROVER models. I have found that the LED will blink if GPIO_2 is used as a signal line and may impact your signal if the GPIO Matrix is set so that GPIO_2 is being used as, say, an A:D or D:A.

GPIO_12 can be an issue as it shares a line with the TCK signal which is used during boot. If the device connected with GPIO_12 starts transmitting on that line, during boot, then you can get failed loads and boots.

All pins on the ESP32 above GPIO_32 are input only.