BROWSER BASED PCB DESIGN

Step 1: The Opportunity

The Distributed Symphony is the largest and most complex project I have pulled off. Once a year I have the unique opportunity to bring a fun experience to a corporate offsite for an audience of 600 executives. For the past few installments, the “fun” has been packaged as a design challenge. The prompt for the first iteration was to build a ball machine that sends a ball on its path for exactly two seconds. Each successive year had an increasing complexity and technical presence. This year I decided it was time to architect an experience that was awe inspiring.

Step 2: Distributed Symphony

The project consisted of one hundred and twenty kits containing all the ingredients needed for a team of five to create a percussive instrument. Each kit included the following items.

• Connected Micro-controller
• Solenoid Ball Dropper
• Instrumented resonator from a Glockenspiel Trigger button
• Ten Wooden Balls
• Building materials
• Artistic elements

Central to this project was the micro-controller. Adding logic and cloud connectivity was intended to enhance the experience and not get in the way. The controller board had considerable functionality exposed in the simplest way possible. Resistor values, power concerns, diodes and capacitors were baked into the board design so that the participants were free to focus on the challenge and not the technology.

Step 3: Take Chances

This project presented the opportunity to build a swarm of custom SMT microcontroller boards. This was new to me but seemed like something worth learning and a major challenge. To design the boards I used Upverter. It is a very cool browser based end to end solution for PCB design and production. Once you get used to finding components in their library, it is easy to use. The boards were based around the very capable ESP32 micro controller. The boards were designed to outlast this project as they were marked for donation to help children learn to code and design hardware. Each board has the following features:

• ESP32 Micro Controller – Wifi and Bluetooth Capable Two PWM Solenoid/Motor headers
• Four Grounded 3.3V GPIO headers
• Two Neopixel Strip Drivers
• Two Capacitive Touch Pads and Optional Headers Onboard LCD Display
• Onboard Single Neopixel
• Onboard USB to UART Programmer –
• 5V Power Bus 3V power Bus

The project only used a single Solenoid Driver, the LCD Display, onboard Neopixel and three of the GPIO headers. The additional functionality has since been used as part of hands on teaching workshops for kids.

Step 4: Plan It Out

The first step in making your custom PCBs is to plan it out. When it comes to hardware design, that means creating your schematic. I used my breadboard to design each section of the total project. As each circuit started working, I carefully translated it into the Upverter Schematic tool. After that I cleared the breadboard and got to work on the next section until the controller board was logically complete.

Step 5: Lay It Out

The next step in hardware production is the PCB layout. This was way more fun than I thought it was going to be, it was like playing SimCity with electricity. The Upverter layout tool is pretty cool and fun to use. The more I worked with it, the more I polished the design and went for style points wherever possible. It is your job to add wires between on the components. There are green lines that highlight connections not traced with copper. The most exciting part of PCB layout is the ability skip ground traces. All they have to do is touch the bottom layer and they are grounded, easy! While we are talking about the bottom layer, that is another thing of beauty. If you have a lot of traces getting getting in the way, all you need to do is drop to the bottom layer, go around the traffic and pop back up on the other side.