ESP8266 Community Forum

- Mon Sep 15, 2014 7:05 am #572

Thanks for your research
But i couldn't find the 0..1V range , conversion time, input impedance etc...

actually this (except the full range 0~1V which is in the latest datasheet) are things that Espressif haven't published yet.
But in the leaked v0.9.1 you can already see how to use the ADC (see esp_iot_sdk_v0.9.1\examples\IoT_Demo\driver\adc.c)

I don't want to be human! I want to see gamma rays, I want to hear X-rays, and I want to smell dark matter ...
I want to reach out with something other than these prehensile paws and feel the solar wind of a supernova flowing over me.

- Mon Sep 15, 2014 9:51 am #578 thanks for that hint.
what disturbs me a little: in this adc module a lot i2c stuff is mentionend. any idea what that means?

is the internal adc a i2c peripheral?

- Mon Sep 15, 2014 10:23 am #579 Yes, it looks like

Espressif just integrated a 10-bit I2C ADC into the ESP8266EX package and connected it to the tout pin. Only single input without PGA (Programmable Gain Amplifier) nor reference voltage

Given the 2µs delay when sampling, it is inherently limited to 500 ksps or less. it will be further limited by the I2C transfer anyway to ~400 kbps if it is not "enhanced I2C".

A dual input ADC with differentil input PGA could have been much more interesting for metering applications for measuring both current and voltage.

- Mon Sep 15, 2014 11:34 am #588 Next version has dual 12b ADC and will work for metering. It isn't finished yet. I just hope there is enough hardware there to process the metering data in real-time. Does this CPU have a hardware multiplier? 16b x 16b or 32b x 32b? If not, it isn't going to do any metering.

Where I get my modules