Tuesday, July 6, 2010

First Surface Mount Board

Here's a couple stills of my last build. It's a self contained audio amp based on an NJM386. I got the chip surplus (I never pay retail for anything) so I had to settle for the small outline surface mount package. I made a carrier board for the chip and free-form wired the rest of the circuit inside an up-cycled Japanese eraser box my son gave me. The whole thing is about three inches square and an inch deep, and contains everything, power supply, amp, and speaker. Now I need to make an instrument to plug into it.

The plastic didn't hold up to the drilling like I had assumed it would, and my layout wasn't real precise, so it's a little funker looking than originally planned, but I think it works ok.

Saturday, July 3, 2010

First Double Sided Board Lives!

Some time ago I purchased the Pulsar system for making printed circuit boards. Since then I've made a number of simple single sided boards then felt ready for something more complex. This is the result. Design wise it's a straightforward Charlieplex display for 9 outputs. The driver holds a 16F688 pic microcontroller. Currently the software is just running a simple test program, but it's implemented with a library that allows me to address individual pixels. I plan to use the 688's uart to stream animation to the display, along with playing animation from ram or eeprom.

Here's a still of the display and the driver unplugged - the driver is pretty light weight.