I bought an ACS712 ampere sensor. The sensor is used to read the ampere changes of a tachometer. The tachometer gets an input voltage of 100 V and sends only 12 V to the optical sensor of the tachometer. The ampere changes for 0 rpm is 5 mA and for 700 rpm is 18 mA. I want to read the ampere change but the ACS712 sensor does not give the reading. However, I tried by INA226 I2C but not giving the value. Can anyone suggest?