The ESP will be integrated into a unit where the only access to it will be via another micro controller that will connect to it via SPI. If there's a need to make flash it in the future (not just an image update via OTA) then I'm trying to figure out how that could be done.

There are some topics about reflashing the bootloader and partition table with ota, which is not supported and has the risk of bricking the device but is possible. Ota over spi can be treated similarly to ota over network. The only way to have full recovery ability would be to be able to set the bo...

Hello, I have an application on ESP-IDF v4.2 that is using the IDF's "mqtt_client" to publish to a broker. The application is passing a CA cert to authenticate the broker.

However, I'm wondering if the data being published by the mqtt_client is encrypted? And if not, is there a way for me to do that?

What if I wanted to flash all of it? Partition table, OTA initial data, app image, bootloader reflash digest, NVS encryption key? Same process or would I need to do something special?

Also, what can I look into to find out how to do this?

I'm trying to understand if the following is feasible and how I could go about it.

If the only way I had to communicate with an ESP32 chip was via another microcontroller using SPI. Could I the SPI to flash the ESP32? If so, how could I go about it?