I just found this service which provides very inexpensive PCB’s for hobbyists. His pricing structure is very simple: $5 per sq inch, you get three copies of the PCB, and there’s no setup fees and free shipping. He’s doing kind of a BatchPCB thing, but somehow has made the cost less expensive. (BatchPCB is $2.5 per sq inch, you get one copy of the PCB, and there’s a $10 setup/shipping fee). I haven’t tried it yet, but he says he needs more people to use his service, otherwise he loses lots of money, so I think I’ll give it a go.

Oh, and did I mention, it’s with 6 mil minimum trace/spacing?

Here’s a comparison chart I’ve been working on that compares various PC-based logic analyzers. I made this mostly for myself because I’ve been wanting to buy a logic analyzer, but most of them are very expensive for a hobbyist’s budget. PC-based ones are a good compromise…they can be cheaper than standalone units since they don’t need all the processing and display hardware. I’m currently leaning towards the $120 Zeroplus unit, it seems to provide the best bang/buck. There is the $50 open source one, but I think I’d wait a bit for more reviews of it, to see how good it really works.

View Chart Full-Screen

I’ll write a review when I do decide on one. Also I know someone designing his own Logic Analyzer, if/when he finishes, I’ll give a link to that too.

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A while ago I decided I wanted to play around with a FPGA – Field-Programmable Gate Array, basically it lets you design new hardware ICs (Integrated Circuits), without needing a multi-billion dollar chip fabrication plant. So I set out to research the available pre-made development kits I could play around with. They’re quite a bit more expensive to get into than microcontrollers (where you can buy a $3 chip and build a programming cable out of some old scraps of wire), so I looked for the least expensive boards that still had a decent set of features.

I ended up making a comparison chart of FPGA development kits, like I said this was over a year ago, so it may be a bit out of date, but the low-end of FPGA’s doesn’t move all that fast. Most of the information is still valid, but you might be best to do some research yourself before you take the plunge. I only considered boards that featured FPGAs from Xilinx and Altera, since I found other vendors are not competitive in the low-cost arena (low-cost was the most important feature to me at the time, I didn’t want to spend $5000 just to play around. And yes, there are $5000 development boards).

View Chart Full-Screen

If you’re curious, I ended up getting the DE2 (with the educational discount). It costs a bit more, but it has significantly more features, such that I’ll probably never run out of stuff to play with.

The ones highlighted in green are the ones I feel provide the best value, and just coincidentally fall at the $50, $100, and $150 price points.
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I’ve finished assembling my little gadget…and it works! As a side note, Flux is super handy, it made soldering the tiny SMT stuff really easy, also I learned a few tips from this video.

I ran into one small problem: on the board, I added a JTAG port for in-circuit programming & debugging. However, my cheapo JTAGICE mkI (not mkII) doesn’t support the newer AVR chip I put on the board. So I had to hack in an ICSP port, hence the four ugly green wires coming out of the middle of the board. But once I got that in, I updated the program I had running on the prototype. There were just some minor changes, IO pins were mapped differently, and the syntax for using Timers was slightly changed.

Now that the hardware is essentially done, I need to write some more software, get a few polished minigames on there.

UPDATE: Please enter your email address, I’m trying to find out if there’s any interest in these devices. If enough people subscribe, it will encourage me to do something about it

You can download a short video, or watch it online here:

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Over the christmas holiday I received my PCBs back from Olimex. They look very professionally made, it’s pretty neat knowing that I designed it completely myself. In the picture to the right you can see the board with a few of the components. I haven’t started soldering yet, but I’ve placed them on there so you can get an idea of how it will look when finished.

I’m waiting on the parts from Allegro before I can finish, I’ve requested samples of their surface mount pieces (previously I only got the ones in the DIP packages).