4.Electronics Design and Production

Electronics Design and Production.

This section includes my first trial electronic design using KiCad and its PCB production using SRM-20 milling machine.Then finally soldering the components and testing their contuinity.

1)Electronics Design using KiCad

My initial list of components to be considered for design were below using XIAO SAMD21 as microcontroller.The components and their pin outs are:

1. Microwave Radar sensor(RCWL-0516) with pin outs-(GND,OUT & VIN.)
2. PIR infrared IR sensor(AM321) with pin outs - (GND,Signal & VCC)
3. PUMP with pin outs - (VCC, GND, Signal)
4. speaker with pin outs - (VCC,RX,TX,GND)

Since the XIA0 SAMD21 was not available in KiCad, i will be using the XIAO RP2040 as my microcontroller as they have similar pinouts.

image source from here

1.1.Working with KiCad (Creating the Schematic.)

Firstly i worked with Schematic by adding the components i want.

1.3.Switching to PCB Editor

Then, i had to start PCB designing.So i clicked on “Switch to PCB Editor” to shift from schematic design.

The schematic editor got into PCB editor.

Now, before i really start with the PCB design, I had to make settings to the design rules like constriants and Pre define sizes and Net classes and these values.

To make border for my board, i clicked on “Edge.Cuts” under the “Layers” and selected line to draw as i wanted to my my PCB boarder irregular shaped and was it was connected.

So this is how my edited PCD design looked.

To look my PCB design in 3D view, i clicked on this icon and it looks this way.

The more detailed information regarding my first trial design of XIAO SAMD21 MCU board is here at my week 6 Electronic Design.

2)Electronics Production for my first trial PCB.

2.1. Exporting F.Cu files and Edge.Cuts files.

My png files exported from Inkscape looked like this.

2.2.Using MODS to convert PNG files to rml

To convert my files, i searched mods from google chrome.

Once i get to the mods, right clicked on the blue icon and selected program.

I continued by selecting ‘open program’ followed by clicking on ‘mill 2D PCB’ under “SRM-20 mill”.

This is how my F.Cu traces looked when viewed.

Here is the final workflow to download rlm file for F.Cu

links for adding library for XIAO Samd21 here

2.3.PCB milling using ROLAND SRM-20.

For my PCB milling, i used 1/64” and 1/32” end mills for making traces of F.Cu and Edge.Cuts respectively.

The setting of Copper Clad board.

Ensured that the copper Clad boards were fixed gently on its bed.

Now, i opened the “VPanel” which was the driver for the Roland SRM-20 milling machine and displayed its panel where i jogged the X,Y and Z axes.

I inserted the 1/64” end mill with the help of allen key and tighten it to its spindle and chuck.

Followed by making Z-axis zero by making use of ‘Curser Step’ to touch the paper placed to act gently on the Copper clad board.

Running the SRM-20 Milling machine.

After completing the milling work, i cleaned the working area by vacuum cleaner.

2.4.Soldering works for my PCB board.

I started soldering and i checked the continuity of circuits after every components to ensure the working.

I continued soldering.

My final board after soldering looked this way and again checked for the contuinity for all the traces and components.It shows fine.

To make convenient to use for this work, i have sketched to show the pins and layout for my PCB board as per the design.

For More detailed on my first trial PCB production can be availed from my week 8 Electronics Production.