The article is being published in collaboration with JLCPCB. It is one of the most experienced PCB manufacturers with more than a decade in the field of PCB prototype and fabrication, they are committed to meeting the needs of our customers from different industries in terms of quality, delivery, cost-effectiveness, and any other demanding requests.


Cell phone or mobile detectors work on the idea of detecting RF signal frequencies. These circuits are built in such a way that they can rectify low signal frequencies with minimal noise. The idea of mutual induction is used when an inductor is put near an RF signal frequency source to receive the signal. The low-power signals are amplified and transmitted to any indication that displays the response, as we did in our experiment with LEDs.

This can be a great exciting project since we can detect if someone is sending or receiving a message, or if a call is coming or someone is attempting to call someone using this simple electrical circuit. As you can see in the image above, this project just requires a few electronic components. This project makes no use of expensive materials. 

The led can be changed with a transistor to control a relay, which can then control a buzzer after the basic working principle is understood. As a result, the buzzer will activate whenever someone sends or gets a message.

Components Required


3D view

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Ordering the PCBs From JLCPCB

Full Process is shown using Screenshots Step-wise.

Now we have got the PCB design and it’s time to order the PCB’s. For that, you just have to go to JLCPCB, and click on the “QUOTE NOW” button.

JLCPCB is also a sponsor of this project. JLCPCB (ShenzhenJLC Electronics Co., Ltd.), is the largest PCB prototype enterprise in China and a high-tech manufacturer specializing in quick PCB prototype and small-batch PCB production. You can order a minimum of 5 PCBs for just $2.

To get the PCB manufactured, upload the Gerber file you downloaded in the last step. Upload the .zip file or you can also drag and drop the Gerber files.

After uploading the zip file, you’ll see a success message at the bottom of the file that is successfully uploaded.

You can review the PCB in the Gerber viewer to make sure everything is good. You can view both the top and bottom of the PCB. After making sure our PCB looks good, we can now place the order at a reasonable price. You can order 5 PCBs for just $2 but if it’s your first order then you can get 5 PCBs for $2.

To place the order, click on the “SAVE TO CART” button. My PCBs took 2 days to get manufactured and arrived within a week using the DHL delivery option. PCBs were well packed and the quality was really good.