Analog input question on ESP8266

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1

Hello, I want to measure current using an ACS712 and a NodeMCU (ESP8266).

The output of the ACS will go from 0,5V to 4,5V - according to the datasheet - so I would need a voltage divider to read those 4,5V (even if the max current that I will be measuring will be 15A). What voltage should I get from the divider? 1V or 3,3V? I saw that there's a divider at the A0 pin. So my guess is 3V (so a 1k:3k divider), at least theoretically, to stay safe because of the tolerances of the resistors...

At this point will the NodeMCU even be able to read this waveform?

SDS00001
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I want to measure the difference between the peaks - in this case it's 1,58V. With the voltage divider it would be 1,185V.

Thanks

2

The Nodemcu A0 has a voltage divider on it. You don't need to add another resistor to scale for your range.

https://forum.arduino.cc/t/using-analog-input-on-nodemcu-esp8266/428337/5

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