ESP8266 Community Forum

- Wed Mar 04, 2015 7:08 am #11256 The internal ADC is a bit noisy in part I think because the esp8266 doesn't have a dedicated voltage reference. However it does work in a pinch:

http://41j.com/blog/2015/01/esp8266-analogue-input/

I think one of the reasons they don't talk about it a lot is that without a voltage reference it's not likely to be very reliable.

- Wed Mar 04, 2015 9:56 am #11262 Also, the MCU should be put to sleep when ADC'ing to minimize noise from the master clock. I don't know if it does this, but the firmware could probably be changed to do it.

- Wed Mar 04, 2015 11:54 am #11280 I wonder if the noisy ADC can be used to our advantage - have anyone tried to use it as a hardware RNG?

- Wed Mar 11, 2015 9:18 am #11794 Hello,

i tried to compile ADC.c and ADC.h.
I want to read the ADC.

The Compiler/Linker gives some errors at functions:
i2c_writeReg_Mask
read_sar_dout

I think the functions are unknown to the compiler/linker

Do i have to add them to ESPmissingincludes?
Are this functions included in all SDKs?