ADC positive offset on 0V

[gjump]

I'm getting a very annoying problem: I have a project using esp12e and on some boards I got wrong ADC readings(using system_adc_read SDK 2.0.0 NONOS), even when I ground the ADC pin I can read a value ~10mV. I tried to change WiFi modes(all of them) but didn't changed significantly.
Any help is appreciated!

Regards,

[ESP_Faye]

Hi,

Could you have a try with the latest ESP8266_NONOS_SDK?

Thanks for your interest in ESP8266!

[gjump]

Hi,

Could you have a try with the latest ESP8266_NONOS_SDK?

Thanks for your interest in ESP8266!

Going to try that.

[gjump]

Hi,

Could you have a try with the latest ESP8266_NONOS_SDK?

Thanks for your interest in ESP8266!

Faye, same problem, same offset. I'll try on more boards, but I got 50% working and 50% with this problem and I'm always checking the voltage at the pin with a calibrated equipment to be sure.
Any thoughts?

Regards,

[gjump]

@ESP_Faye
Things i've tried:
Switched the ESPs between boards to to be sure that isn't the circuit, the problem followed the ESPs.
Wrote a simple code using system_adc_read_fast(), wifi off and got the same result, with the ADC pin grounded it reads 10-12 points.
Yesterday I've built 3 more boards, 2 ok and 1 with this offset. I have now 3 with offset and 4 working.

Don't know what's going on;

Regards,

[Jamartox]

Dont you have the down arrow to the left of the thread title?

[gjump]

Dont you have the down arrow to the left of the thread title?

Down arrow? I don't think so. What's that for?

[gjump]

Anything? Our client is asking for answers!