Analog Light Sensor + Light Sensitive Switch using OPT101

You may have seen many light-sensitive switch circuits based on an LDR sensor. Usually, the sensitivity of the LDR based light sensor is poor. We wanted a very sensitive light switch hence we decided to make a circuit based on a light sensor rather than LDR. After a little research on the internet, we found the OPT101 light sensor chip which includes a photodiode and a transimpedance amplifier in one package. The OPT101 light sensor provides an analog voltage output linearly proportional to light intensity.