Board Layout


96 Pin Ball Grid Array (BGA) package
A33-OLinuXion Top layer
CK/!CK: 0.2mm
addr[0:15], !WE, !CS, !RST, DBA[0:2], ODT, !CKE, CAS, RAS: 3mm
DQ[0:7]: 1.27mm
DQ[8:15]: 1.27mm

Power Supplies

Max efficiency for an LDO
Hot loop
Power Distribution Layer

Bill of Materials Generation

The Build

Bare Bords
Pasted Boards
Pre-Reflowed Bords
Finished Boards!


The Great Divide

Pros of “two board system”

  • You can rev each board individually. If you want to switch regulators on the power board and you have the inventory of the compute board, you don’t have to discard the compute boards.
  • Noise isolation, you’re physically moving all the switching regulators away from the sensitive electronics.
  • Different board manufacturing capabilities. I might choose 1oz copper for the compute and 2oz for the power. Compute might need 4 layers while the power only needs two layers.
  • Vertical space gain. There is a lot of horizontal board space taken by the BGA, RAM, SD card and radios. However, there is very little vertical space required. By stacking two boards, I’ve doubled the horizontal space.


  • Cost. It’s more expensive to build two boards instead of one.
  • Signal Integrity. If you have high-speed signals running between boards, you have to worry about the SI of the board-to-board connector.
  • Assembly time. Gotta plug em together, yo.
  • Mechanical design and interface.
RTL8188CUS Step File
RTL8188CUS Symbol
CUI’s PBO-15C-5
CUI’s Recommended Design

The Mech

Low Cost all Charger




Building things.

Love podcasts or audiobooks? Learn on the go with our new app.

Recommended from Medium

How to center a div tag in CSS — horizontal & vertical align

#34 Find First and Last Position of Element in Sorted Array 在排序數組中查找元素的第一個和最後一個位置

How to fix Amazon prime error code 6085

How to fix Amazon prime error code 6085

Networking questions and answers

Difference between Azure Backup & Azure Site Recovery.

Create your GitHub Page with GitHub Actions to Continuously Integrate and Deploy

Creating a Rails api easy version!!

Software Development: Front End vs Back End vs Full Stack

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store
Ryan Walker

Ryan Walker

Building things.

More from Medium

A little Squeezebox USB controller

Raspberry Pi and Embedded Linux Adventure (PART1: How to Start)

Remote Physical Input Device on Linux based devices

Wifi Access Point using a Raspberry Pi