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Convert ADC values in Amps - Current Sensor Allegro ACS722-20AB

Hi to all! I’m using an ACS722 current sensor and I have to transform the adc values in amps. How can I do it?

When I use the function read(), on CoolTerm I see values around 0,500. How can I convert this values in amps? Can you help me?

PS: I’m using a board NUCLEO_F401RE with ADC 12 bit resolution, and the sensor has 66 mV/A of sensibility (20 A version in AC current).

Let me know,
Regards

Hi Raffaele,

AnalogIn() reads the voltage as a fraction of the system voltage. The value is a floating point from 0.0 (VSS) to 1.0 (VCC). For example, if you have a 3.3V system and the applied voltage is 1.65V, then AnalogIn() reads 0.5 as the value.

So if your system is using 3.3V, then the amps should be (0.53.31000)/66 = 25A.

But it looks incorrect, would you use a multi-meter to first check the value read from ADC is correct?
And please also check the sensitivity again in the datasheet.

Thanks,
Desmond