Hey Brooke, it looks like you are using the same form factor of the teensy for you sensor board. Very nice!
1 Like
What made you decide to use the bus pirate instead of another platform? (like Arduino)
Those pictures look great! How did you create those? I am just getting started with the software, so it’s new to me.
I am using the Bus Pirate as it is a much quicker iteration cycle. I don’t have to change code, compile, upload, run each time I need to change the communication a bit. Unlike what I would need to do on the Arduino/Teensy. I just use a terminal like putty/hyperterminal and connect via serial. From there it is very easy to send hex, bin, or dec strings to the chip to characterize how it work without any of the associated code time. Once I have that figured out, then I head to the dev platform (Arduino/Teensy) and code up my findings from the BP.
I personally find it to be more fun and a faster feedback loop using the BP. Plus I am finding I don’t have to spend as much time coding as I already have a mental model of how to talk to the chip as well as my own written “spec” for the commands I plan to use.
Which pictures were you wondering about? The 3D ones of the boards are a built in feature in KiCAD. When you are in the PCB Editor (pcbnew). You go to View | 3D Viewer.
For the Bus Pirate photos, I used an iPhone w/ SnagIT. The background is a gymnastics mat.
I released my first Arduino library. You can now search for the DS7505 library right in the Arduino/Teensy software!
Re-ordered my CE Header board and SensorBoard due to solder mask clearance issue. The most recent version of KiCAD seems to have changd the defaults for the solder mask pad clearance and solder mask pad min width. This changed has caused issues with my 4 most recent boards where the solder mask is “pulled away” from the ground and power planes exposing a ring of copper right near the pads the need to be soldered causing shorts.
Please post an image of the difference you have both in hand. Would be interesting to see what the boards look like side by side.
Testing MB85RS64V SPI FRAM with Bus Pirate. Very cool 64Kbit chip. It acts like flash memory. You can write to it and it retains the data between power off/on.
Oh yeah! FRAM is great. It’s finally starting to come down in price a little bit, it has been around a long time but the patent is up soon i think. I know TI started putting it into MSP430 chips.
I made a comment about this in the former build log ond posted the compared images.
(Perhaps this image will not be available to all)
Are these the settings you changed. If so do you know the old/new values?
OLD Pads Mask Clearance
Solder Mask Clearance 0.007874015748" = 0.2mm
Solder Mask Min Width 0
NEW
Solder Mask Clearance 0.002" = 0.0508mm
Solder Mask Min Width 0.004" = 0.1016mm
All of my older boards that worked fine
Solder Mask Clearance 0
Solder Mask Min Width 0
Here you go. In each photo, Left is the new and Right is the old. I haven’t done any soldering yet, but the mask looks the way I would expect now. Huge difference.
You can click on the images to get the full size original.
NOTE: On the Good board, you see a tiny reflection around the through holes. That isn’t an actually spot where the mask is missing. I had to use a flash where I am to help show the missing mask on the bad board.
Back
Front
I just noticed that the silkscreen is partially missing on the back of the bad board too. That’s odd. I didn’t do anything to change that.
1 Like
If you think it’s a manufacturing issue, be sure to let the OSHpark folks know. They’ll at least make you another set of boards.
1 Like
Hi Brooke,
You can see by the screen shots, the only value I changed was the Solder Mask Clearance. Once I realised what my issue was, I went back on previous boards and saw that this value was also zero. I therefore set mine to zero and checked it carefully against the Gerbers and this worked out fine and has ever since.
The settings from the failed board
The settings from the corrected board
1 Like
I did report the issue 2 different times since it was happening on multiple boards and in both cases it was explained that my settings were the issue. At the time, I didn’t notice the silkscreen. And since changing my settings looks to have resolved the issue, I am hopeful just to move on.
Chris, do you have anyone you connect with to see if the KiCAD issue can be given a new look? It sounds like the current default isn’t a reasonable one and thus will likely cause issues for people new to creating PCBs. I am not sure how I would have handled it if the first PCBs I created from KiCAD cost me money and didn’t work, and I didn’t know how to figure out what was going on or who to talk to about how to fix it.
Here’s the issue I found: https://bugs.launchpad.net/kicad/+bug/1563744
1 Like
There are a couple developers over on the KiCad forums, might be a good idea to bring it up there. At the very least, it will give visibility to others as well, should the change take a long time.