Page 1 of 1

TX pin current leak in deep sleep

Posted: Sun Jan 06, 2019 1:46 am
by dontsov
I have a LED connected to ESP TX pin.
Image

The LED is very bright. When I turn off pin and call deepSleep the LED doesn't turn off fully. 4uA are leaking through pin. See the picture:
Image

If i touch TX pin by oscilloscope it turned off and scheme consumption decreased. Sometimes it turned off by finger touch...

Code: Select all

 Serial.flush(); Serial.end();  --- doesn't help
twi_stop();    //turn off i2c line   --- doesn't help
ESP.deepSleep(0, RF_DEFAULT);
//..... 50 ms .....
// EN set to LOW by attiny
What I do wrong?

Re: TX pin current leak in deep sleep

Posted: Tue Jan 08, 2019 3:51 am
by ESP_houwenxiang
Can you try to set tx pin to input mode when entering seep_mode?

Re: TX pin current leak in deep sleep

Posted: Mon Mar 29, 2021 9:56 am
by dontsov
It doesn't help.
Interesting ,that if I don't use UART in my code I see TX only in booting (bootload message). During my loop LED is full OFF, but in deep sleep it shines dusk.

Re: TX pin current leak in deep sleep

Posted: Tue Mar 30, 2021 4:17 am
by ESP_Sprite
4uA is very little... are you sure that e.g. contaminated flux isn't causing leakage from 3.3V? That would also explain why the LED is full off when not in deep sleep (as the pin is driven hard-low then)