WEEK 6 – Electronics Design

Assignments

Group Assignment

Use the test equipment in your lab to observe the operation of an embedded microcontroller

Individual Assignment

Simulate a circuit
Use an EDA tool to design an embedded microcontroller system using parts from the inventory, and check its design rules for fabrication
Extra credit: try another design workflow
Extra credit: design a case

Group Work

Our group work is accessible HERE (add the link)

Individual Work #1

PCB Design Process

Project Initialisation

Step 1: After reviewing a few EDA platforms with my instrutor, such as KiCad, Altium, Cadence, and EasyEDA/IcDEA... I decided to use IcEDA for this week first trial. EasyEDA/IcDEA is a free open-source EDA software. The IcEDA is the Chinese version which can be set in English, and the EasyEDA version is the international version.

Step 2: This is the home interface of the software - Click "New Project" to create a new project

Step 3: Define file name and its location on my laptop, and then click "Save"

Step 4: The new project file is created and the software interface updated

Step 5: Double-Click P1 to make visible the skecth page and frame template

Import Components from the Component Library

Here is the process to import my first component, the XIAO-ESP32-C3, which I decided to use for this practice exercise.

Step 1: Click the "Library icon"

Step 2: Select the "JLCEDA library", then type the name of the board we are looking for, the XIAO-ESP32-C3, then click the "Place" button for the relevant one (see below "Hardware Specification Analysis" section)

Step 3: Click anywhere in the displayed page space to place it on the schematic page P1

Step 4: Repeat Step 1 to 3 to import from the JLCEDA library in IcEDA the other required components for my electronic design scenario as listed below:

x1 LED (NCD1206G1)
x1 Resistor (150Ω) - as recommended on the datasheet of the LED
x1 3-pin Head for SG90 Servo
x1 4-pin Head for Ultrasonic Sensor HC-SR04

Hardware Specification Analysis

Before going any further in my Electronics Design, I must better understand the specifications and Pin definitions of the hardware, the XIAO-ESP32-C3. To do so, I looked for a "Getting Started" tutorial on the XIAO-ESP32-C3.

Pin Assignment Plan

Here below is my plan for connecting the pins:

Pins (IAO-ESP32-C3)	Signal Name
A0	Ultrasonic Sensor TRIG
A1	Ultrasonic Sensor ECHO
D7	Servo PWM
D9	LED +
GND	LED - / Ultrasonic Sensor / Servo PWM
VCC	Ultrasonic Sensor / Servo PWM

Circuit Design Implementation

Schematic Design

Step 1: Connect the components to the appropriate pins of the IAO-ESP32-C3 micro-controller as shown below, using wires and connectors:

Step 2: Convert schematic to PCB. It is needed to "Confirm" to create a new PCB and place it on the same board. It is also required to "Apply Changes" to confirm importing changes information.

Here is the result:

PCB Layout and Design

Step 1: Now, we need to re-arrange the layout of the components on the PCB to optimise its size, clarity and routing complexity.

Step 2: Define the outline of the PCB.

Here is the result:

Step 3: Create the routing by clicking "Auto Routing" in the "Route" top menu, and check/set the parameters (Design Rules) before clicking "Run".

Here is the result: Looking at the result in the image above, we can identify two problems:

The wire connecting Pad 2 is crossing the connection pads for the battery, and therefore should relocated
The blue wires are on the bottom face of the board and should be moved to the top face for manufacturing simplicity

Step 4: Wiring improvement according to the two above listed recommendations.

OHHHH!!!! MISTAKE...

I forgot to connect the VCC and the GND to the Pinhead 😦 😦 😦

Final PCB Design

Wire View

2D View

3D View

Individual Work #2

For this second PCB Design work, I will be using Fusion 360.

PCB Design Process

Project Initialisation & Import Components from the Component Library

Step 1: Import "Eagle" EDA Fab library to Fusion 360

In Fusion 360:

Step 2: Fix the "fab" library to look for component in the right side bar

Step 3: Search for the desired component (e.g. XIAO_ESP32_C3, LED, resistor, pinheads)

Hardware Specification Analysis

(Refer to the same sub-section from the previous Individual Work #1)

Pin Assignment Plan

Here below is my plan for connecting the pins:

Pins (IAO-ESP32-C3)	Signal Name
A0	Ultrasonic Sensor TRIG
A1	Ultrasonic Sensor ECHO
D7	Servo PWM
D8	LED +
D9	LED +
D10	LED +
GND	LED - / Ultrasonic Sensor / Servo PWM
VCC	Ultrasonic Sensor / Servo PWM

Circuit Design Implementation

Schematic Design

Step 1: Connect components to the micro-controller by using the "Net" tool

Step 2: Connect the resistors to the LEDs and micro-controller

Step 3: Look in the fab library for a 5x2 Pinhead and place it in our schematic design

Step 4: Reposition the 5x2 Pinhead to the left of the mricro-controller and connect the 2 components together

PCB Layout and Design

Step 1: Switch the view to 2d PCB mode (from Schematic mode)

Step 2: Draw the shape of the board... 1st try NOT CREATIVE ENOUGH!!!

Step 3: 2nd try... Draw the shape of the board using the Outline Polyline and Outline Spline tools - within the BOARD SHAPE tools section