Pop quiz hot shot

Electrons are a flowin ;D

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Pin 7 on the Accel isn’t routed which is used to set the i2c address.

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solder blobs works. And don’t they have default addresses?

I’d like to see your skills solder blobbing a QFN :whistle:

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Alas @ Bill is very much still the legend and correct about pin 7, and sadly it appears there isn’t a default address hence the need to tie it to VDD or GND.

So poos…

And as Dave mentioned about solder blobs…hahahahahahahaha not!..as you can see not all QFN’s are equal. Both QFN’s in the image are 0.5mm pitch with the RS485 IC have exposed pads on the sides as well as under so with a bit of Solder Fu and child sized fingers and a microscope you might get away with it but as you can(not) see the Accel only has pads on the underside of the package and not on the sides.

datasheet time:

To select/exploit the I2C interface, the CS line must be tied high (i.e. connected to Vdd_IO).

and

The slave address (SAD) associated to the LIS3DSH is 00111xxb where the xx bits are modified by the SEL/SDO pin in order to modify the device address. If the SEL pin is connected to the voltage supply, the address is 0011101b, otherwise the address is 0011110b if the SEL pin is connected to ground.

Did you scan I2C for both addys, just in case it worked? Are you setting CS in code?

@ Brett - indeed I RTFM before and after…seems I was lacking caffeine and the heinous pressure of client expectations lead to the loss of a postal address. And yes CS is tied correctly…

Frustration thing is that part of the design was CTRL-C and CTRL-V’d from another working design but somehow the missing GND got lost in translation…

grounded in translation. There’s a movie in that I reckon

@ Justin - [quote] the heinous pressure of client expectations [/quote]

…as beads of sweat appear on his forehead, dripping down, salt stinging the eyes…

So are these boards going into production anytime ? or just a one off like all the previous ones ?

@ Designer - More than likely…

Also most other creations have gone into limited production, you just need to ask as I have been too busy with other mundane choirs to put them online.

But in saying that…things are afoot…wondrous silicon based things…and websites…and… :wink:

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