Stephen's Weblog

Ah, it’s been a while.

Since I opted to stop posting on a fixed schedule, that seems to have eliminated any hope of regular updates – oh well.

So, I have been largely tied up in a (Very big) project that’s still secret, I’m not saying much about it. But there have been a few bits of progress in other areas – Most notably, I finally got a CNC controller board populated!

Isn’t it lovely?  I certainly think so, after all the work that went into getting this far :)

Sadly, I won’t really get much further at the moment (need to get back to an all-consuming secret project), but this has marked a pretty big milestone in a few of my projects (the reflow controller also works pretty nicely!)

I’ll be sure to take some time and write up these when I make some more progress (or just get sick of working on the more important stuff again)

Progress! At long last!

Over the past month I have been designing a CNC controller for various small projects I’ve been kicking around (oh things like 3d printing, building a pick&place, and some other random thoughts)

Being the hopelessly stubborn sort that I am, I decided to build it from scratch. The design work for something like this is something I enjoy immensely, and while I don’t always get everything right the first time (There are a few inefficiencies, but nothing terrible), it’s been a lot of fun and a good learning experience.

Here’s an image of the final board design, and past the break is a very long thread of text and images showing the steps getting to this point:

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Ah! It’s been 2 weeks again already; Work speed for me always varies a lot, but I’ve been unlucky lately: I put in a lot of effort for one project and then it stalled right near the end. I’ll go back and finish it and write it up sometime soon though :)

In the meantime however, I have received the reflow controller PCBs I mentioned a month ago! Some pictures are up on flickr, one is below – I don’t have it working yet but that will become a priority pretty soon.

Coming next:  I’m currently working pretty hard on a CNC controller for stepper motors and some other things; As usual my ideal is to build my own solution instead of using any existing one, so I’m desiging my own now. I will post a full writeup on it once I have it completed, but don’t want to share any details at the moment.

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…

One big thing I’ve been working on lately is bitbox! Bitbox started as just a clever idea, but it was just so interesting that I had to make it :) Bitbox is essentially a tiny music player that will play 8-bit music – sorta like a boombox, but a bit smaller ;)

I still have some software work ahead of me, but here’s the (nearly) final circuit board:

(I say nearly final because I did go on to make some tweaks after taking this image)

Read on for a train of WIP images and more information… (more…)

I haven’t done anything worth mentioning, so here’s a picture of some PCBs! :)

This is the USB Jtag PCB I previously mentioned, and I had it produced in a group PCB order managed by Laen – They turned out nice and came back pretty quickly, I’ll definitely be sending him more PCBs

As I was on vacation though, I just recently ordered the parts to complete these boards, and haven’t got them yet. I’ve also been thinking about priorities and am working more heavily on some projects which I won’t blog about :)

Things are still developing though, keep watching and I should have more to talk about in 2 weeks.

Despite having 2 weeks for this, I haven’t actually completed anything notable; So I’m just going to post some WIP images of a PCB I’ve designed to do general purpose programming (Generally jtag, but also AVR)

I’ve been working out the concepts in software using the modified USB stick (as I mentioned previously) but just haven’t had enough time to allocate to it yet. Soon, though.

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So, many of you use JTAG?

I’ve been using JTAG for many years now, which started with FPGAs, and has mostly been for CPLDs and FPGAs since- but it’s also a pretty widely used protocol for programming and debugging mid range microcontrollers all the way up to high end CPUs. I’ve always wanted to look into how JTAG worked in more depth, but never really had the time.

Now, I do have some time (and some projects which depend on JTAG hacking) – so this post will go into the world of JTAG. (more…)

Remember the PCI card from a few weeks ago?

Not too long after that, I did send out an order to manufacture some boards – and this last week they finally arrived! I’ve assembled a few, tested them, run into a few problems, solved them, and finally got a pretty basic PCI Port-80h debug card working.

In this post I’ll walk through these things, and talk some more about the PCI interface.

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Oh, finally…

So, this post is a little bit late as well, I almost didn’t manage to make this work :) I’ve been now tinkering with writing a USB device stack for my USB stick for literally the past two weeks now; Being a new space, I’m used to the idea of having issues, but between incredibly stupid bugs, very minimal documentation, and errors in some critical hardware documentation, this has been quite a challenging project.

On the plus side, I now have my USB stick behaving as a virtual com port – so it will be trivial to write extensions and make it start to do really useful stuff (haven’t quite got around to that yet, so expect a part 3)

Additionally, in the process I’ve become pretty familiar with  how USB works, and I’ll try to more simply define it for those who are interested in getting started.

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