Stephen's Weblog

Not a whole lot has happened since my last post; at least not a whole lot of projects that I’m talking about :)

I’ve been busy working on a Windows Phone 7 game, writing VHDL for one hardware project, thinking through a second hardware project, and will be working on yet another hardware project soon ;) These I will probably post about eventually, but not until they’re further along…

Some of these projects are explicitly going to have the first revision done in 2 weeks though, so I should have plenty to talk about then!

I have started getting set up to compile code for the LPC134x chips that I’m using in everything recently, as I will need to be able to program them shortly – I’ve got the devkitARM toolchain installed and am modifying the GBA compilation toolchain to be able to compile for these devices. Just started that earlier today and not quite done yet.

I’ve also designed circuit boards for a toaster oven reflow controller (including images below) – This is a two-board solution, one deals primarily with switching the high voltage using optoisolated triacs (thanks eagan for pointing me in this direction, I was originally thinking of relays) – The other board is another LPC1342 with a flash chip to store configuration and run data. It has some buttons and an LCD for user interface.

These will be in Laen’s Jan. 3rd order, and I will be trying oven reflow very shortly after they come back :) I also have come up with a few other interesting things to control with this, and will have to report back on my success with that at a later time…

Nothing really big to show off, but a few things are moving along:

First, I’ve started a Flickr page! Pictures I take (typically of stuff I’m working on or taking apart) will be auto-uploaded to http://www.flickr.com/photos/sgstair/

I don’t always update the descriptions but any questions posted in the comments will be answered :)

Second, there has been some progress on bitbox; After some early failures, I now have the bitbox_test board working! I misread the datasheet for the LPC134x chips initially – The USB bootloader requires an external crystal; I’m not quite sure why I thought otherwise. For the bitbox I am attempting to do USB without a crystal even though the internal RC OSC might be slightly out of spec. Maybe I’ll need to revise it.

Next I’ll be writing some initial firmware for this board and then all things bitbox should start to move along.

I also ordered some laser cut acrylic for the test fixture, and should get that back in a bit over a week – this test fixture has been interesting to design – it’s a little overengineered in hindsight, I’ve since designed another fixture (for another project) that’s far simpler. Below is my laser cutting pattern with a few designs:

I’m using Ponoko to have this produced – will have to talk more about it next time.