ESP8266 Community Forum

- Mon Feb 01, 2021 8:51 am #90384

I don't know how you have the rotary encoder connected, but my guess is that GPIO15 (D8) is not low when you are trying to download until you disconnect the 3.3 volts.

Thank you and you are correct. I replied to my own post before noticing you'd responded but that was exactly the issue. I sorted this late last night and didn't have time to post before I had to go to bed.

- Mon Feb 01, 2021 8:54 am #90385

Like @mgsecord62 says, check which GPIO's can be used without problem, which when taking precautions and which you "Can't" use:

ESP8266-NodeMCU-kit-12-E-pinout-gpio-pin.png

ESP8266-NodeMCU-kit-12-E-GPIO.png

For more tips and tricks, see this excellent and helpful page.

Thank you very much for your response. I also found that page, which is indeed very helpful and figured out the solution late last night and that was the problem. I am not familiar with the internal wiring of the rotary encoder but it is now clear that GPIO15 was being pulled high so either disconnecting Vcc or GPIO15 (labelled as D8 on the NodeMCU) fixed the issue.

Thanks for taking the time to reply.