You would want to span across the entire board so that the shield board is stable when mounted to the base board. It’s common for an Arduino shield to have dimensions that differ from the dimensions of the base board, but the main requirement is to set the width so that you hit the pins you need to use on the main Arduino board. Mechanical dimensions for the Arduino Uno R3 (left) and the Arduino Mega 2560 R3 (right). Once you’ve finished schematic capture and you’re ready to import the design into a blank PCB layout, you’ll need to set the board dimensions to sit at the width of the Arduino base board. It’s tempting to jump into the design and start making schematics, but you’ll need the connector pinouts early in the design process so that you can place nets on the right pins in your design. The first step might be the most obvious, but it’s tempting to overlook the first step in starting an Arduino shield board design: find the mechanical dimensions of your Arduino shield and the connector pinouts.

Throughout this article and in some upcoming articles/videos, we’ll show several tutorials on how to use Arduino and shield boards, including some tutorials on application development.

If you’re just learning how to use PCB design software and you want to create a custom shield, go download CircuitMaker, it’s free to download and free to use. If you’ve never designed your own Arduino shield board, follow along with the instructions shown below. You can even design these boards to be reconfigurable if you like, similar to the shield board shown above. These boards have the same form factor and board-to-board connection that matches your favorite Arduino base board, but you have freedom to control many of the basic aspects of the layout in your shield board. Are you ready to connect custom circuits to your Arduino, but you’re tired of using a breadboard to build up your circuits? It sounds like it’s time for you to design a custom Arduino shield.

Circuitmaker pcb