Reader [Osgeld] is a board-layout ninja. He populated this 4×4 LED matrix board without having a layout plan to start with. Watch it develop in slideshow format to see the art work he performs. The display is driven by a shift-register and he’s included all the proper parts like resistors and transistors, yet he makes everything fit. Why is this amazing? He’s using uninsulated wire and not a single one of them crosses another wire. He’s physically designing a printed circuit board, routing the traces as he solders away. He’s built this to use with an Arduino shift register tutorial and our only question is where is the header to hook this board to a microcontroller?
The build has two main components; an LM4950 audio amplifier and a center channel speaker he picked up for $3 at Goodwill. The circuit used is straight from the datasheet and he’s provided the four necessary resistor values for you in his writeup. An old set of headphones was butchered for the audio connector and DC power can be provided by any 6-12V source.
The final circuit was built on some protoboard. The speaker housing has plenty of room to fit everything in for a nice finished look. Pretty simple, and except for the IC, this should be an easy salvage project for most folks.
Making a PCB is very simple; it does not consume a lot of time and the results look professional. After reading this How-To and watching the step by step video, you will be able to make your own PCB in your workshop using just a few inexpensive materials.
Many people use protoboard and point-to-point wire everything, but needing multiple copies of the same circuit is the reason that forces many away from using protoboard. After making your first circuit board, you might not point-to-point wire anything again!