New pin numbering ?

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    I wonder what would be the reason (a strong reason in order to brake the rule) for this BME680 sensor from Bosch to number the pins clockwise ?

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I ran across the same thing with some intelligent RGB chips.  No idea why.

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because the chip in this house are placed upside down.

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Maybe is meant to be mounted on the BOTTOM of the board?

 

 

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Designer has dyslexia.

 

JC

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Now I'm not sure if you are joking but

 

A normal chip has the bounding pads up, then a connector to the pin.

 

I this house the pads  (more or less) is the pin and therefor mirrored compared to the normal house.

Last Edited: Tue. Dec 4, 2018 - 09:10 PM
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    My opinion is that even if the silicon inside the sensor is outsourced and no matter in what position sits, the information that goes out in the wild can be accommodated so the end user would see a normal counter-clockwise pin numbering.

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and that is the case if you look at is as a soic chip (on the board top left is 1 as normal)

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I’m told the designer was ‘just following orders’!

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at least you are warned in the datsheet:

think somebody messed it up with the pin1 marker in top and bottom view of his design package. Changing the spec to meet the mistake is a lot cheaper than having to re-do a package design.

 

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I can't believe that any package would break the convention i.e. pin#1 is top left.
Surely the epoxy package has always got the indent / notch / dot / stripe in the same top left position.
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If the fabrication factory has placed the wafer into the package the wrong way round, it will just have to scrap the whole batch.
Likewise, any documentation would be revised.
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Sh*t happens. Fix it. Move on. Let the lawyers work out whether the mistake was the Fab or Bosch.
.
David.

Last Edited: Wed. Dec 5, 2018 - 07:33 AM
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david.prentice wrote:
I can't believe that any package would break the convention i.e. pin#1 is top left.
A long time ago, in the beginning of the SMD mass production I read an article from a frustraded PCB design firmware company because there did not seem to be much consensus about the pinout of a SOT-23 package.

 

I think they finally decided to strip the pin numbering altogether from their libaries and only labeled the pins for transistors "b", "e", "c" with a warning to the user they should check the datasheets of their smd transistors carefully to deterimen where those pins should go and pin number could not be trusted.

 

In some datasheets the pinout is forgotton altogether, or buried on page 23something which is also quite annoying.

 

In "elektuur", Dutch magazine (Later renamed to "Elektor") there once was an article about a project with which a lot of peopble had trouble reproducing. It turned out that a particuar fet in TO-92 was made with different pinouts. Type number was the same, but the part with some suffix to the part number, or from a different manufacturer had 2 of the pins swapped.

 

Stuff like this has happened before, and will probably happen again.

 

Also read somehwere that the atrocius half hole pin offset of arduino boards was due to a last minute edit by one of the designers and the connector got accidentally bumped in the PCB software.

And instead of doing some decent testing and correcting that pinout they just shipped it to millions of customer who have now trouble mating a vero board with an arduino board.

 

About the "shields" as they tend to call the plug in PCB's.

Bought some from China and had trouble fitting them.

Turned out that the distance between the left & right header pins on the arduino board were 19*2.54mm while the distance between the connectors on the TFT panel from mcufriend are 1.27 mm wider.

With a bit of gentle bending they still fit together though.

 

 

david.prentice wrote:
Fix it. Move on. Let the lawyers work out whether the mistake was the Fab or Bosch.
  Agreed. It would have been nice of Bosch or the Fab if they had corrected this silly mistake instead of documenting it for the world to see.

Paul van der Hoeven.
Bunch of old projects with AVR's:
http://www.hoevendesign.com