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.


I created the CLP-DUINO with the aim of helping the learning in Ladder language with a low cost equipment and that can also be used in the automation industry. The design was based on the Atmega328P-PU but also compatible with the Atmega8-16PU.

Inputs and Outputs

The CLP-DUINO board has six 24Vdc digital inputs and four relay outputs on the board and a dedicated output for the buzzer where all must be pre-set in the software as shown in the image.

USB Connection

For the usb connection I used the IC CH340G which does not require the use of the oscillator crystal. This makes it easy to program on the board without having to remove the MCU using the serial usb converter already present on the board via the type B usb connector

Expansion of Inputs or Outputs

On the PLC-DUINO board we also have six more digital ports that can be counted as inputs or outputs.

Note: These digital ports are directly connected to the microcontroller

Step by Step to Order the PCB at JLCPCB

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 “QUOTE NOW” button. JLCPCB are also 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 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 if the file is successfully uploaded. You can review the PCB in the Gerber viewer to make sure everything is good. You can view both 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 10 PCBs for $2.

Note that by default on the website your PCB will be green. I chose to do it in blue color but you can choose from other available colors.

To place the order, click on “SAVE TO CART” button.

I have chosen to ship by Registered Air Mail to avoid customs fees but you can choose another shipping method. After entering my shipping address I selected Pay Directly but you can ask for Review before Pay if you are unsure if you have any errors in your project. Before finalizing your order you can use the promotional code JLC-REBE to get a discount and then click pay.

Assembling the PLC-DUINO

Final Considerations

After performing the assembly and testing I was very happy with the final result. I appreciate the partnership and support of JLCPCB that makes my projects more professional.

Also follow my work on youtube and my products on my website:

Jefferson Bueno channel on Youtube

Jefferson Bueno website