Page 1 of 1

Configure GPIO4 as ADC Input

Posted: Fri Apr 13, 2018 11:39 am
by kishan patel
Hello,
I am using esp_wroom32(esp32 dev-kit).So,can i use GPIO4 as an adc input?
Thanks in advance,
Regards,
Kishan Patel.

Re: Configure GPIO4 as ADC Input

Posted: Fri Apr 13, 2018 12:25 pm
by ESP_krzychb
Hello kishan patel,

Yes, you can but there are some restrictions.

Re: Configure GPIO4 as ADC Input

Posted: Fri Apr 13, 2018 1:37 pm
by kishan patel
Okay thanks,
And can i use GPIO12 as a DTR pin?
Thanks again,
Regards,
Kishan Patel.

Re: Configure GPIO4 as ADC Input

Posted: Fri Apr 13, 2018 2:31 pm
by ESP_krzychb
Do you mean DTR (Data Terminal Ready) input to control serial communication?
GPIO12 or MTDI is one of Strapping Pins and should be either pulled down or pulled up on power-on reset.
External device connected to GPIO12 should not pull in opposite direction on power on reset, or ESP32 will likely fail to boot.

Re: Configure GPIO4 as ADC Input

Posted: Sat Apr 14, 2018 4:24 am
by kishan patel
Okay thanks,
Yes,DTR (Data terminal Ready),i want to use it as an output.Is there any restriction to use GPIO12 as a DTR configuration?
Thanks in advance.

Re: Configure GPIO4 as ADC Input

Posted: Sat Apr 14, 2018 10:11 am
by ESP_krzychb
GPIO12 is also one of dedicated JTAG pins.
If you plan to use JTAG then its operation will interfere with an application toggling DTR.
Apart from that I do not see issues with using GPIO12 as an output.