ESP-01 RX or TX as digital input/output?

[zodiac]

@Costas

@zodiac

4,17V

This is significantly lower than 5V.
.

But still significantly higher than 3,3V I can report no ill effect due to 5V Vin also, think there is no risk at all.

[zodiac]

@Gunner

But as for using the TX/RX pins as normal GPIO… have you tried it yet? or just asking first. I can’t afford to replace mine so I am not about to test it yet

My four relay board was connected to single esp01, so yes, it’s possible as long as you don’t use serial prints. Works fine.

[Amorphous]

For those that are interested, I tried what was suggested above last night. I figured worse case I can buy “a real ESP” as was also suggested .

For reference my sketch connects to Blynk and also has OTA and wifiManager libraries and code. I removed all Serial commands from my sketch, and added some lines to toggle GPIO1 high for 1 sec then low for 1 sec over and over. This successfully produced 5 volt pulses thru my ESP-01 adapter that has LLC. However it seemed to kill the OTA functionality. I would need to do more testing to confirm it wasn’t a fluke. I then tried the same thing for GPIO3. This also successfully produced 5 volt pulses and this time I was still able to load code OTA.

[Gunner]

Sounds good… did you need to enter any special setup commands for the GPIO3 or did it just work?

[Amorphous]

Nothing special. Just pinMode(3,OUTPUT) in setup and digitalWrite command in loop like normal.