Inspiration

Not too long ago, I came across the the #BadgeLife trend. People would make PCB into artistic badges.

 

They will design with different shapes like cartoon characters. I was inspired by these and always wanted to make a badge for myself.

 

This is an example of a badge in Defcon.

 

Project Introduction

When I saw this contest, I feel it came at the right time.

I first thought of this project a few months ago, when my country was in lockdown due to the virus pandemic. Due to shipping delays, I was only able to get all the components and complete the programming a few weeks ago.

 

My project is a PCB badge to be worn with a lanyard. It is meant to be a conversation starter during interviews or events. Importantly, it has the outline of my name as the shape of the board.

 

The heart of the circuit is an STM32F103RE IC chip

In the middle, I added a 12x8 LED matrix. There is also an ADXL345 accelerometer and a Bluetooth module too.

 

Design

The design is made using EAGLE PCB software. I simply added a large text and then traced out my name on the board outline.

 

 

Manufacturing

 

I sent the Gerber files to JLCPCB. I ordered 10 boards buy they sent me 12 boards. Price was cheap for about USD15 inclusive of shipping.

 

The outline of my name is very clean and I am impressed that they manufactured it so well.

 

Soldering

 

I have experience in soldering 0805 SMD before. So for this project I decided to try 0603 SMD for all the passives.

 

But the difficulty was the SMD LEDs. The LEDs were made of plastic casing so if I wasn't careful, I will melt the casing and spoilt the LED. I did not have any solder paste around so I could not do reflowing. I spent the most time on careful soldering all 96 LEDs (12x8 matrix)

 

Programming

I connected ST-Link programmer from a Nucleo board using breadboard wires. I programmed it using STM32 Cube IDE.

 

So far I have gotten the accelerometer and LED matrix working, which I will show in the video below.

 

I have not gotten the Bluetooth reliably. I chose the JDY-10 module from eBay to keep costs low. This is because I realised the module uses Bluetooth Low-Energy (BLE) which my PC doesn't support.

 

My phone happens to supports BLE so I may have to code an app for it later on. My plan is to show patterns or text controlled via the Bluetooth app. I do not have much experience in BLE, hopefully, it is not too different.

 

Video Demo

 

The first video is testing the accelerometer. It moves a dot around the screen.

 

This next video is trying out a "water" mode. It looks like water moving around a cup.

 

This last video, I made a game. This is a replication of doodle jump.

 

Photoshoot

 

And lastly, this is PCB Art, so we need a professional photoshoot.