Brooke's Build Log


#1

This will be my CE Build Log


#2

Teensy Breakout. I plan to use a keyed connector here vs pin headers when I don’t need to stack. Boards and parts are in.

Top



Bottom


#3

Teensy Sensorboard. Boards and parts are in.

PCB Top



PCB Bottom





Layout Front



Layout Back


#4

Hey Brooke, it looks like you are using the same form factor of the teensy for you sensor board. Very nice!


#5

I show how I learned to access a MCP9808 temperature sensor with the Bus Pirate.


#6

I show how I learned to access a DS7505 temperature sensor with the Bus Pirate.


#7

What made you decide to use the bus pirate instead of another platform? (like Arduino)


#8

Those pictures look great! How did you create those? I am just getting started with the software, so it’s new to me.


#9

@tnichols,

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.


#10

@peteyfeet,

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.


#11

I released my first Arduino library. You can now search for the DS7505 library right in the Arduino/Teensy software!


#12

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.


#13

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.


#14

@ChrisGammell,
Excellent idea, will do.


#15

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.


#16

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.


#17

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)


#18

@Steve_Mayze,

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


#19

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.


#20

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.