This page gives advices that I have collected as a result of my experience in designing and making hardware systems. I do not pretend this is the best practices in the area. I use this as a set of notes to follow when I'm designing a new board.

Schema design

Verify the following items:

• unused pins
• connector layout (for routing, evolutions, understanding, isolation)
• decoupling with capacitors
• protection of power supply
• control logic to validate
• do not neglect the pull up resistors

PCB design

Verify and take care of the following items:

• global positioning of components. There must be enough space between them so that I can solder, repair them.
• components should be aligned. This simplifies the power supply routing, the mounting.
• Ground layout
• Vcc layout
• enlarge the width of wires (keep it to the max). I try not to go below 0.4mm (16 mil)
• enlarge the clearance to the maximum. 0.4mm (16 mil) for wire, 0.25 (10 mil) for pads and wire
• run the Eagle DRC check with a larger clearance and fix the problems.
• assign a specific Class for the power supply lines and setup that class with a larger width 0.8mm