Hi there
This should be a simple one, but I don’t understand ESPhome so far:
In ESPeasy, I could use D3/4 as I2C. Now, in ESPhome, if I assign and connect them, I’m according to the docs using the special boot mode pins. Thus, the esp won’t boot into mode 3.
Unfortunately, I need 6-10 I/O pins. How can I use D3/4 for I2C?
Cheers, Lukas
D1 and D2 are the usual pins for I2C.
You can use D3 and D4 as i/o as long as they are pulled high at boot.
See the table lower down on this page: ESP8266 Pinout Reference: Which GPIO pins should you use? | Random Nerd Tutorials
If you need more i/o than is available consider using an I2C i/o expander or an ESP32.
thanks for your fast reply. How can I pull them high at boot by software?
May lets rephrase it: why can I use D3/4 with ESPeasy but not with ESPhome on the same hardware?
No by hardware, physical pull-up resistors and you must ensure that whatever is connected to the input is active low only occasionally so it is unlikely to affect the boot process.
I have no idea. I have never used ESPeasy, but the D3/4 thing would be relevant no matter what firmware you are using.