Week 08

This is my 8 week at FabAcademy. This week I have learnt a lot about PCB machining. The assignement of the week consisted of:

group assignment: - characterize the design rules for your in-house PCB production process - submit a PCB design to a board house individual assignment: - make and test a microcontroller development board that you designed - extra credit: make it with another process

Group assignement

Regarding the gtoup assignement we were checking all the fabrication rules of our Roland CNC machine that we use for CNC machining. Also we submitted a PCB design to a board house. Please see the full description of our group work in the following link: https://fabacademy.org/2025/labs/aindustriosa/week08.html

Individual assignement

Regarding the individual assignment, I designed a board that includes one three-pin connector, one-four pin connector, along with a led and a button. First of all, based on the electronic design I submitted in week 6, I updated it to include the button:

Then I connected one side of it to the ground and the other to the 9th connector

Latter in the PCB design application I fitted the design to include the button just in between the holes I created for possible conenctions

To see how all the components look like physically, I searched for them in our inventory and put them over an existing PCB we had before

Once the dersign was ready in the KiCad PCB editor, I exported the result to a svg file to subsequently manipulating it with Gimp

Then I created a new layer in gimp

Crop the area that did not belong to the PCB and changed the layer to white

Then I selected the contour and dots and switch them to black

Subsequently, I resized the PCB to fit with my cooper base for machining

Then I merged all visible layers to just have one layer with the edge cut and another with the tracks

Then I inverted the colour to have as black what needs to be cut

Then I selected the canvas sizing again but not for resizing but to just get the exact size of my PCB in order to latter manipule it with VCarve

The result after the mainpulation of the image in GIMP looks like the following

Finally, I exported the PCB design from GIMP to png in order to use it in VCarve

Once in VCarve, I selected the tracks and edges to trace them and generate a vector for calculating latter the machining

Then I created two tools, first a mill of 0,4 mm and latter one with similar characteristics but 0,8 mm, the latter being used for the edge cutting.

Then I calculated the CNC trajectories with VCarve

As well as the edgecuts

Finally, I also including some bridging from preventing the pull out of the cut piezes during machining

To finally export as png and save the VCarve file to read it directly in the Roland CNC

Once the design part was done, I started machining the PCB in the Roland here you can see the action

Finally, I welded the different parts of the PCB

However this did not worked properly, my first welding was terrible, so I needed to fabricate a sencond PCB and welding again… I did it, and this time it did worked properly. Here, you can see the new PCB

Once welded, and assured the continuity of my circuit I programmed in Arduino a code for flashing the LED. For that I used a code similar to the one I elaborated in week 4 (embedded programming) but using the digital pin D10 which is the one of the ESP32C3 which is connected to the led, the resulting code was

void setup() { 
 // put your setup code here, to run once:
 pinMode(D10, OUTPUT);
}
void loop() {
 // put your main code here, to run repeatedly:
     digitalWrite(D10, HIGH);
     delay(1000);
     digitalWrite(D10, LOW);
      delay(1000);
 }

Then I dowloaded the ESP23 component library and connected my PCB to compile and upload the code. This worked properly and here you can see the flashing light in my first produced PCB!!

Files for download and replication

Here you can download all the files of the assginment including the files from KiCad KiCadRar

Here you can dowload the Arduino code for the flashing light ArduinoFile