Regarding LDR in circuit

[19bmc009]

sir why do we connect one end of LDR from A0 and one end from GND.

[akshayan.sinha]

@19bmc009

We have answered a similar question on the forum -

Output of light intensity monitoring system

@arigelabhuvaneswari That’s a great question. I’ll help you understand the basics in a simple way. You know that LDR stands for Light Dependent Resistor, so depending on the light(photons), the resistivity decreases. (More light, more conductive) Now, the circuit we building by making the following connections is also known as a voltage divider circuit. Usually we use 2 resistors to make the circuit and provide our desired amount of voltage and input to the Vout side. In our case, we are us…

[dks082001]

look first of all one end of ldr is connected with 3v3 and another with analog pin i.e. A0 then a resistor is connected in series i.e. one end of resistor will be A0 and another at ground . so its like you are placing 2 resistors one ldr and one 10k resistor in series and supplying voltage (3v3) and compleating circuit (by connecting to ground) and in between you are measuring voltage change (by analog pin) . since light will affect the resistance of ldr hence voltage will change.