Week Seven

~ Electronics Design ~

Key activities / Learnings / Inspiration

This week, I learned a different circuit design software other than eagle, KiCard. I also explored TinkerCircuit, a simplistic circuit designer marketed toward children. This helped me to comprehend the connections and arrangement of the different components. TinkerCircuit actually lets you export your design as a .brd file which is what Autodesk Eagle uses.

Here is a tutorial you can use to learn Eagle Software.

I decided to use KiCard, because I want to learn how it works.

Assignment: Redraw the echo hello-world board, add (at least) a button and LED (with current-limiting resistor) check the design rules, make it, and test it ; extra credit: simulate its operation

Here I used KiCard and referred to the echo Hello World board by Professor Gershenfeld.

Acknowledgement

Due to the shortage of electronic materials in the lab, I added other compenents on my PCB. These are components (the RBG LED and LDR) I may need to work with in following assignments.

Step1: Design the Circuit and the Edge

I created a new project that I called echo board

After, I added all components. Once all components are added the screen looks like this:

Routing the circuit board.

Saving the png file image for the traces:

Importing the png image in fabmodules to generate the path and .rml file for the milling machine

Saving the png file image for the outline:

Importing the png image in fabmodules to generate the path and .rml file for the milling machine

Step 2: Check the design rules (DRC)

After the above, we need to make sure that the thicknes of the traces and spece between them are the correct ones. To edit so we neeed to go to DRC icon and put 0.04mm everywhere.

I also did the Electric Rule Check (ERC)

One of the feature in Kicad is to check the schematic for any electrical rule error. So i tested that out after preparing my schematic.

Step 3: Printing the circuit

Preparing the bed and fixing the FR4 board with a tape on the sacrificial board

We use this tool to mill the traces on the board.

Checking if the traces were done correctly.

We use this tool for deeper cutting (of the edge).

This is how it looked like after milling.

I used that black scratcher to remove the top materials.

Result

Step 4: Add the components

Below is how I calculated the resistor for the LED:

I used 499 ohm resistor because it was the only available in the lab higher than 140 ohm. I avoided to use resistor with less resistance because it could burn the LED.

I added the LDR in series with the resistor.

Step 5: Testing

After, I connected the ISP programmer that I made earlier, to the other USB port. Used the ribbon cable to connect the FabISP and the Hello board using the two six-pin headers connected to each other.

Uploaded the codes:

Receiving input from the push button and lighting the LED:

Test :

Files: