# Designing a Bluetooth-Controlled Car PCB Using Eagle

## Introduction

In this blog, I will walk you through the process of designing a **Bluetooth-controlled car PCB** using **Eagle**. The design includes schematic creation, PCB layout, and best practices for efficient circuit board development. We will also discuss how to set design rules, navigate the **Bill of Materials (BOM)**, and ensure smooth execution of the project.

## **Schematic Design in Eagle**

### **1\. Creating the Schematic**

When working with **Eagle**, it's essential to start by designing a clear and well-structured schematic. Here’s how I approached it:

* **Component Selection**: Using the **Eagle component library**, I added the necessary components, including the **Arduino, motor driver (L293D), battery clips, resistors, and screw terminals**.
    
* **Proper Net Labeling**: Each net was labeled appropriately to ensure clarity in connections.
    
* **Power and Ground Connections**: I ensured that all components received the correct power supply (+5V VCC and GND) from the schematic.
    
* **Best Practices:**
    
    * Use **bus and labels** instead of direct wire connections to avoid clutter.
        
    * Double-check **pin connections** before proceeding to PCB layout.
        

## **Setting Design Rules in Eagle**

Before moving to PCB layout, it’s crucial to set **design rules** to meet manufacturing standards. The provided design rules specify clearance, width, and drill sizes. Here’s how I applied them:

1. **Go to** `Edit -> Design Rules`.
    
2. **Set clearances** (minimum spacing between traces, pads, and vias) as per manufacturer guidelines.
    
3. **Define minimum track width** to ensure proper current flow.
    
4. **Check drill hole sizes** for component leads and vias.
    
5. **Enable DRC (Design Rule Check)** to verify that the schematic and board comply with the rules.
    

By following these steps, I ensured that the design met the required specifications and was ready for fabrication.

## **PCB Layout in Eagle**

### **1\. Converting Schematic to Board Layout**

Once the schematic was finalized, I switched to the **Board (BRD) layout** in Eagle:

* **Component Placement**: Placed components logically, ensuring short and clean traces.
    
* **Power Traces**: Used wider traces for **+5V VCC** and **GND** to handle current efficiently.
    
* **Routing Traces**: Routed signal traces carefully, keeping them as short as possible to minimize interference.
    
* **Via Placement**: Placed vias strategically to connect top and bottom layers when needed.
    

### **2\. Running Electrical Rule Check (ERC) and Design Rule Check (DRC)**

Before finalizing the board, I performed:

* **ERC** to detect any errors in the schematic.
    
* **DRC** to validate that the PCB meets the design rules.
    

## **Navigating the Bill of Materials (BOM)**

The BOM provides a detailed list of components used in the design. Here are the key elements:

| Part | Value | Device | Package | Description |
| --- | --- | --- | --- | --- |
| G1, G2 | AB9V | AB9V | AB9V | 9V Battery Clip |
| IC1 | L293D | L293D | DIL16 | Motor Driver |
| JP1 | \- | PINHD-1X6 | 1X06 | Pin Header |
| M1, M2 | \- | W237-102 | WAGO Screw Clamp |  |
| R1, R2 | 1K | R-US\_0204/5 | 0204/5 | Resistor |
| U$1 | Arduino-BPlace | Arduino-BPlace | \- | Arduino Diecimila/Duemilanove |

Using the BOM, I ensured that all components were correctly placed and connected in the Eagle layout.

## **Media**

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1742518494198/e2a3179f-f1a4-4109-afe4-3945b66f4d20.png align="center")

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1742518498429/c624c022-d99e-4c5e-9211-c1c77a4001aa.png align="center")

## **Conclusion**

Using **Eagle**, I efficiently designed a Bluetooth-controlled car PCB by following best practices in schematic design, setting design rules, and validating the board layout. By carefully navigating the **design rules** and **BOM**, I ensured a functional and manufacturable PCB. This project provided valuable insights into **embedded systems and PCB design workflows**.