Can we just use an ESP32 NodeMCU for example to program an ESP32-CAM? I saw a lot of people programming ESP32-CAM using an arduino Uno, can we do the same for ESP32 NodeMCU? Of course, in the "Arduino as ISP" programming mode. If we can, is there anything more that I need? if not, why? and are there any other solutions to program it?
Moreover, I want to use ESP-IDF which is better than using the Arduino GUI app.
I have discovered how to use the ESP32 NodeMCU as a serial interface. In other words, make the ESP32 traverse ALL of the serial communication to the TX & RX pins directly without any interference. When you press the "RST" (Reset) button, it turns off, but when you release your finger, it will turn on. However, when it is turned off, it traverses all the serial communication to the TX & RX pins, which can then be used to program and contact with the ESP32-CAM. Of course, you can't keep pressing the "RST" button all the time, instead connect the "En" (Enable) pin to GND which will then disable the 3.3 voltage regulator (Same as if you were pressing the "RST" button), in other words, turns the ESP32 off. And then, connect any two GND pins together from both of the ESP32's. At last, upload your program to the ESP32-CAM.
All you need to program any ESP32 (Cam or not) is a serial interface. How you make that serial interface is up to you.
Most ESP32 development boards have a USB to UART converter on them which you can use just like on an Arduino - keep the ESP32 you're using for the programming in RESET so it doesn't try and respond on the UART.
You could also program the "programmer" ESP32 as a UART passthrough to connect the USB UART through to the other UART so you don't need to mess with holding in RESET.
