Sadly it doesn't look like I will ever be able to buy a DNA board. A while back I contacted Curt to see if he would entertain the thought of sharing the board layout so I could try my hand a making my own. I was actually surprised that I got a response but it contained words such as "..commercial venture.." "..build it for cheap.." "..undercut our market..". Fair enough.
With that door closed I decided that this time was probably as good as any to learn how to use Cadsoft Eagle. I've always had an interest in electronics even thought I am a Mechanical Engineer by trade. I reckoned that Eagle couldn't be much different to the CAD/CAM packages I am familiar with.
Cadsoft offers a freeware version of Eagle for boards under 3"x4". This is plenty of room for most hobbyist. There is a bit of a learning curve to the software but there are lots of online tutorials as well as the invaluable YouTube resource.
I gathered together all of the info pertaining to the DNA venture and set to work on the schematic for the main board. Curt had posted a "napkin engineering" version of it that got me started. I listed out all the components that were mentioned in the blog and gathered all of their data sheets. The puzzle was starting to come together but I was still missing sections
The saving grace was the pictures of the board layout. This held the key to the parts I was missing. I separated the layer colors into individual images and was able to complete the sections of the schematic that were missing.
https://lh5.googleusercontent.com/_F...86Ys=s378-p-no
With the schematic sorted, I moved on to board layout. Curt had obviously spent a good amount of time laying out the board as efficiently as he could. There are some neat tricks and what I consider strokes of genius that he used. Again the pictures of the layout were vital in reproducing the board. I imported the images into Eagle's layout editor and adjusted the scale and position until the top 2mm header and bottom .1" header matched exactly. From there on it was a downhill battle as I only had to "color within the lines" with the trace routing. The only issue I ran into really was how Curt filled and enlarged main traces on the board. It seem he used the "Rectangle" tool to block in larger traces and fill areas. This works but is a really hack way to go about it. Eagle's "Design Rule Check" errors out when you have over lapping sections. As a newbie Eagle user I didn't have the skill set at the time to use the polygon tool too correctly to fill the areas. Instead I stuck to copying the board as closely as possible. My final layout was roughly 98% accurate to the real thing. There are a couple differences in the silk screen but the traces and pad layouts are pretty much identical.
https://lh5.googleusercontent.com/vY...w459-h466-p-no
With the DNA board layout finished it was time to get a prototype made. OSH Park has a sweet PCB prototyping service which offers 3 copies of your board @ $5 per square inch. I didn't fully realize the low cost of the DNA until I uploaded my Eagle file.
https://644db4de3505c40a0444-327723b...vsj3oOH7/i.png https://644db4de3505c40a0444-327723b...vsj3oOH7/i.png
I couldn't believe it. $1.70 for 3 boards shipped to my door?!? I just spent hours and hours copying a board that costs $.57 each. It blew my mind.
Next in line, was reverse engineering the button and OLED board. With my Eagle skills improving it wasn't long before I had a completed reproduction of the button board. Again I couldn't get over how cheap it was to get these boards manufactured. $3.50 for 3.
https://644db4de3505c40a0444-327723b...7BkG8H8B/i.png https://644db4de3505c40a0444-327723b...7BkG8H8B/i.png
I had most of the OLED board layout finished when the first order from OSHPark arrived. Yup, these are small boards.
https://lh3.googleusercontent.com/hZ...w439-h466-p-no
https://lh3.googleusercontent.com/za...w282-h466-p-no
Curt mentioned in his email that he doubted I could assemble a DNA board. I've soldered some pretty small stuff by hand. 0603 components and Attiny13's in QFN packages. Do I intend on hand soldering A DNA board? Not really as I can make my own solder paste stencil and reflow it with either a hot air system or modified toaster oven. I do plan on trying to hand solder one just to prove I can do it.
I finished up the OLED board and put together a parts order from Mouser. Even in small quantities the cost of the components for the main board are only $10. As you can see in the picture below I finally figured out how to “tent” the via’s on the board with solder mask. This should help when assembling the boards. The OLED board being the biggest of the lot came in at $5.15 per batch of three.
https://644db4de3505c40a0444-327723b...MS2fmWzD/i.png https://644db4de3505c40a0444-327723b...MS2fmWzD/i.png
This brings us up to right about the time that Curt reemerged on the forum and it looked like the project was moving forward again. Excellent! Maybe I won't have to attempt to load the DNA alpha code release. It would be great if I could load a polished version of the DNA software.
Unfortunately that thought was short lived. Curt is once again MIA. Guess I'm going to have put on a programing hat and start learning about that...
So to where does that leave us now? Can we call the DNA project officially dead as a commercial venture or do Curt and Simon intend on releasing a board to the general public in the near future (by the new year)? Inquiring minds need to know as I would have no problem releasing all the work I have done reverse (dirty) engineering the project. In my opinion this is the only way this project will ever move forward in any capacity.
The DNA project was presented as an open source project but seems to have transitioned to a commercial venture. The development utilized the open source model and used the community for its collective knowledge. Unfortunately this is where it stopped. The board layout was only shared as images and software has not been updated since the initial release. I feel the project has failed because the community was not allowed to actively participate. There definitely is community interest. Sadly we are relegated to the side lines, offering advice but only allowed to watch painfully as a very potential project dies because the founder loses interest. I'm sure we all have projects that have fallen by the way side. I just hope that the Curt is willing to hand the torch off as there are many of us that would like to see this board come to fruition.
