MBlock Coding

Step 1 — Create Variable

First create a variable named:

value

This variable stores the LDR sensor reading.

Step 2 — Main Program Blocks

Full Logic

When Arduino Uno starts up
    forever

Step 3 — Read Sensor Value

Inside forever block add:

set value to analog read pin A0

Explanation

• LDR sensor is connected to A0
• Arduino continuously reads light value
• The reading is stored in variable value
•  

Step 4 — Add Condition

After reading value add:

if value > 500 then

Explanation

• If light is bright,
• sensor value becomes greater than 500

So condition becomes TRUE.

Step 5 — LED ON

Inside IF block add:

set digital pin 8 output as HIGH

Explanation

• HIGH means ON
• LED connected to pin 8 glows

Step 6 — Else Condition

Add ELSE section:

else
    set digital pin 8 output as LOW

Explanation

• LOW means OFF
• When light becomes low,
• LED turns OFF

Final MBlock Logic

When Arduino Uno starts up

forever

    set value to analog read pin A0

    if value > 500 then

        set digital pin 8 output as HIGH

    else

        set digital pin 8 output as LOW