Judson Belmont asked 1 year ago
- Your 99% clear and understandable tutorials are great. However, the early one on esp32 pinout may assume a greater understanding for a noobie than should. Regarding booting, there is a clear listing of which pins must be high and which low. However, I don’t see how I have control over those pins state. I have the recommended esp 32 wroom dev kit and find that as long as I disconnect the 3.3 volt pin at boot up, it works. otherwise every combination of using the boot and reset buttons are to no avail. Is there a better way to boot up? 2. in the esp32 relay tutorial with the 12 volt power supply, you use the vin pin to power the low voltage side of the relay. Why use the v in for power and not the 3.3 Volt pin? I like the “v in ” use because it does not interfere with booting for me. Can I always use the v in pin to power low voltage items on the breadboard? I thought that the v in was to provide power to the Microcontroller in place of the USB port so as to unharness from the computer. Thank you for your indulgence and all the work you perform to help so many.
Sara Santos Staff answered 1 year ago
Hi.
During boot, the ESP32 will put the correct pins HIGH and LOW to be able to receive the code. You don’t need to worry about that unless you have some peripherals connected that will put those specific pins in a different state.
In some ESP32 boards, you just need to hit the upload button and it will do everything automatically, while in others you need to press the BOOT button. It depends a bit on the board model you’re using.
We use the VIN because it outputs 5V in our specific board and it was best for that kind of relay. But it depends on the board and the model. I recommend that you check with a multimeter what output voltage you have on the VIN pin.
When the board is powered via USB, you can use the VIN pin to power other components.
When the board is not powered via USB, you can use that pin to power up the board.
I hope this is clear.
Let me know if you have more quesitons.
Regards,
Sara