# 1st IOT project. Using Light monitoring device

So i am using the basic 10 k resistor with 3.3 V LDR. Now the max data coming is 1.02 thousand. when i switch off the lights, its varying. but if i start my flashlight from a far location , just that there is a little light around the LDR, it shows 1.02 thousand. Isn’t that wrong ? like under a bulb and under a faint light, it is showing the same reading. when i put my hand on LDR, the reading varies a little but not too much

1 Like

No it is not wrong, the highest value it can read is 1.02 thousand, I also tried the same way you did.

but doesn’t that bring up the paradox? like a little light is giving the same rating and whole bulb is also giving the same reading ?

I think its right.The highest value i got is 1.02 thousand.When i covered the entire room and made it completely dark, i got 761.

friends just try to use the device for 1 whole day, you will find some changes definitely.

The minimum value of an LDR in sunlight is around 100 ohm. So it is giving a value of 1.02 thousand. The same resistance can go up to 10M ohm in darkness. I have tried by placing the Bolt IoT Module in the darkness and achieved the minimum value as 661.

You might try to connect the 330 ohm(orange orange brown gold) resistor in series with the LDR.
If the value 1.02thousand is being shown when the LDR is placed in light then it might happen the internal resistance in your ldr is different than the standard one.
Just connect the 330 ohm in series
And if the problem persists connect the ldr with the 5V pin.
Cheers!

Its not wrong,
The maximum value it showed for me was 1.02 thousand.When i switch off the lights and cover the LDR with my hand the values varied and the least i got was 291

try to use the 330 ohm resistors it solved the problem for me

It is not wrong. The LDR you have can detect a maximum intensity of light corresponding to 1.02 thousand so if it is under light of intensity >= max intensity (corresponding to 1.02K) it will show 1.02 K only. However, you can vary the LDR’s sensitivity by using different values of resistors in series with the LDR in the voltage divider circuit.

Check the connection of the resistor in the bolt iot cloud .
and LED connection if it is fixed tight ,then the value is varied