ACS712 - Current Sensor Module

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ACS712 - Current Sensor Module

By trackerj
- Tue Jun 02, 2015 6:50 am #19212 Hello,

In the process to find better isolated current measurement solution I am exploring the posibility to use the ACS712 Current Sensor Board with the ESP8266.

As they are all over the place, why not :)

Main identified problems to solve:

ASC712:
5 Vdc power supply device
measure positive and negative 5/20/30Amps, corresponding to the analog output 100mV/A BUT
"ZERO" point, means no test current through the output voltage is VCC / 2 =5v/2=2.5V !

ESP8266:
3V only device
ADC range max: 0-1V

So far, the solution that I found was to use a difference amplifier:

Image


If you know any other way to do it or have any related ideas, please feel free to share :)

For reference: ASC712 Current module meets ESP8266
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Re: ACS712 - Current Sensor Module

By trackerj
- Fri Jun 05, 2015 2:46 am #19519
Baoshi wrote:Pretty much the same. Input impedance higher.


Do you have some ESP8266 datasheet technical details regarding ADC input impedance or is just an assumption?

By the way, anybody out there have an idea when might be possible to see a decent datasheet for this chip?
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Re: ACS712 - Current Sensor Module

By trackerj
- Sat Jun 06, 2015 5:10 am #19631 Part 2 of the story : programming the ACS712 Current reading function.

Question for any of you using frequently the ASC712 sensor: it is all the time so noisy or is just mine ?
Using the Voltage Level Shifter and DC op amp module with a big number of reading gives decent result but in case of direct voltage divier the noise level is very high.
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