Light Intensity Monitoring System


Got the result of Light Intensity Monitoring System, My first IOT project!
2nd Project is on the way…!’
Thanks @Boltiot!


@roshnidash827 Congrats! :slightly_smiling_face: :ok_hand:


Why does the LDR always show 1.02 thousand if light is sensed and some value between 200-500 if no light is sensed?
And what does this mean : Some students have received an LDR with internal resistance which is different from the standard. Try using the following combinations in the given sequence

  • 3.3v - LDR - a0 Pin - 10k - gnd
  • 3.3v - LDR - a0 Pin - 330 - gnd.


HI Sir.I have successfully made the connections,then made my product,wrote the code,linked it to my bolt module through cloud.But whenever i try to deploy configuration ,it is showing"no hardwire configuration exists for this device".Please help .



Please send the screenshot of your hardware configuration for further investigation.


I think so you have not saved the hardware connections you made and make sure you variable to A0 pin.for further details share the screenshot.



@chinmayat11 I also had faced the same problem.You can try a 330 Ohm resistor instead of 10k Ohm resistor. Different LDRs are compatible with different values of resistors…Here is the image of the graph with a 330 Ohm resistor.!



There might be something wrong in code. Recheck code and connections


may be you wouldnt have given power supply to the iot module or might be module wouldnt have been connected to wifi


I got my output.


Please go through the following steps:

  1. Please check the configuration of the product. (Code and hardware)
  2. Make sure all your hardware connections match with the ones given in the training. Also check the validity of the connections. (Are the sensors properly inserted into the pins of the Bolt wifi module )
    3 Always save and link your products.


Hi @chinmayat11 !
Circuit explanation is as follows:
The A0 point is the analog point and it takes in the value of voltage between 0 to 1.The taken value say 0.576V is converted to a binary number of 10 bits,by the in built ADC converter.So each value read by A0 pin is given by 10 bit binary number whose decimal equivalent ranges from 0 to 2^10-1(this decimal equiv. is shown in the output table).
Now in our case at bright light LDR,resistance lowers down and it gives less drop so A0 pin gets high value.For dark case resistance increases,and gets good drop so A0 pin gets low value.
Thank You!!


when first time on a device i have got the table graph in using bolt cloud then i disconnected the bolt device then when i again connected it all the previous data was lost and the data points were 0 in plant monitoring project…

Is it that the data gets lost when bolt device is not online…??


No, it doesn’t
I changed the resistor(my LDR had an internal resistance) and deployed it again. The data count continues. You can see your data values even when the device is offline.


@awantika.ashi123 Please change the time period on the graph page. By default, only the last few points will be displayed on the graph.


Due to the internal resistance of LDR which is high in some kits so the 10k ohm resister would not be able to resist that so it is suggested that if you face any problems like this than use 330 ohm resister inspite of 10k ohm resister