Saturday, January 17, 2009


I'm excited to announce that I found a CMS/shopping cart combo that is OSS and looks quite nice. I found a conversation here about PCB CAD. They mention Joomla and VirtueMart. Checking out both projects' homepages, I'm conviced they are a worth trying out. This means once I figure out what rules there are from work to sell PCBs on the side I can start working on opening my own e-commerce site. Wait. My server just died. SOB. Really? It had to die just right in time for me to get into selling stuff online? Meh, back to work rejuvenating my server.

Friday, January 16, 2009

Electronic rubix cube

Here is a preliminary image of the electronic rubix cube. By using identical boards for each of the sides, manufacturing costs can be reduced. The board uses an ATmega168 or similar chip and 27 LEDs. I figure it will cost somewhere around $50 to make. 1.8"x1.8" squared, if this thing worked, it would be pretty screaming.

Saturday, January 10, 2009


This is the latest revision of my motor controller using a couple h-bridge controllers I got from ST. This is an attempt to finish the robot that I started in high school. The main thing that I'm missing is a control system.

I have two power window motors that are beastly and a basic frame. My original motor controller used some power bjts and never worked. This design I hope will work and be much more efficient.

I am using two h-bridge controllers, VNH2SP30, from ST. They are actually designed for automotive use, such as controlling power window motors. Perfect.
At 12V they can pump out a continuous 15 amps. The chips are 40V tolerant, and are ok with surges up to 30 amps. They have a current sense output and two can be used to control one motor for up to 30 amps continuous!

The basic outline is designed to be a shield for my arduino diecimila. The problem with this design is that I want to add an XBee module, but stackthrough connectors are expensive and hard to come by. Samtec makes them, but my mail server is down, so I don't want to sample them.

My plan is to redesign the controller with an Atmel AVR built in as well as an XBee module. With an XBee pro, this would be a great drop in replacement control system for a lot of basic RC Vehicles. Once I add some headers for sensors as well as a place to add a fan for cooling, it would be a great platform for robotics.