I am rather pleased on how this turned out. I did miss one trace. though I blame Diptrace! The two traces where touching in the schismatic but they where not linked. Its easy enough to tell since linked traces have relatively large circles on them. I fixed the schismatic and re-loaded the Gerber files onto OSH Park. You can see the small wire I put in place in front of the middle switch.
Once I added that wire it started working exactly as I wanted it it. And As I was hopping my IBM T42 Thinkpad (best laptop EVER by the way) power cord power the bbps perfectly. Powering it by both the 5V USB or the 16V power cord outputs the same exact voltage. The USB data pass-through also works as expected. I have also created a Project page. You can find links to OSH Park as well as the Mouser parts list page.
I started a new small project. I am calling it bbps (Bread Board Power Supply). I realize there are quite a few of these out there already. They are all missing one thing that would be a REALLY nice feature. USB data line pass-through. Maybe it is because I am mostly interested in making PC peripherals but I am somewhat surprised that there is nothing out there already that has the feature set I am looking for. A good potion of this design is straight from my loststone project.
Features I am looking for in a breadboard power supply…
- Independently selectable 3.3V and 5V for two power bars.
- Optional shutdown a single power bar.
- Provide power from both a wall wart or a USB connection.
- ESD protection. (I think I went a bit over board on this front)
- USB data line pass-through
- Stable. Don’t want it flopping around.
I have place the OSHPark order and will be placing the Mouser order shortly
Two years of blood sweet and tears and it has finally come together! A fully opensource trackball from circuit board to software.
Check out the project page for more details.
I really put some time into fleshing out the PCB design. I am quite pleased with this first revision. This was my first attempt at designing anything like this so allot of time was spent learning what I needed to do and then how to do it. It was a bit overwhelming when I first create the PCB from the schematic (Image 2). Cluster-fuck is a good way to describe the “ratlines”. However once I got the hang of the interface I found it rather fun to lay the components out and run the traces, almost like a puzzle. I had to redo a few parts but overall it went fairly smoothly, it just took some time.
There are no design rule or net connectivity errors, which in programming terms means “it compiles so it must be correct” 😀 I will be taking a break for a week or two. Then come back and go through each component and each trace in both the schematic and layout files (again). The less then fun part. Then on to OSH Park