FRDM-STBC-AGM01 schematic?

[tungdao]

Hi,

Is there any document for the FRDM-STBC-AGM01 schematic that I can download and see? I tried to search for one but could not find any. The quick guide that came with the board does not help much.

Also, is pin SA1 of the FXOS8700CQ exposed on the FRDM-STBC-AGM01 breakout? There's no label indicating a pin is SA1.

Thanks.

TD.

[reyes]

Hi TD,

Sure, you can find the FRDM-STBC-AGM01 schematics here​.

SA1//CS pin of the FXOS8700CQ is exposed as “SA1_CSB_8700” connected to pin 3 on jumper J10 on the FRDM-STBC-AGM01 board as can be seen in the schematic.

By default, SA1 is connected to GND via resistor R8, but it can be changed to be connected to VDDIO_8700 if you populate resistor R5 (and depopulate R8).

Have a great day,

Jose Reyes

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[tungdao]

Thanks Jose.

The schematic makes sense. But I'm still having a hard time to find the label SA1_CSB_8700 on the FRDM-STBC-AGM01 board: http://cache.freescale.com/files/sensors/doc/support_info/FRDM-STBC-AGM01-QRC.pdf

If possible, do you have a full list of labels for all breakouts on the  FRDM-STBC-AGM01 board? Right now the quick guide shows only few of them.

Thanks.

[reyes · Accepted solution]

Hi TD,

The labels that are not named on the FRDM-TSBC-AGM01-QRC is because those pins are not connected (compare to the schematic).

And the labels of the BRKT-STBC-AGM01 can be found here.

So, the “SA1_CSB_8700” signal is connected to pin 2 of the Jumper J4 on the BRKT-STBC_AGM01 board and on pin 3 of Jumper J10 on the FRDM-STBC-AGM01 board.

Have a great day,
Jose Reyes

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[tungdao]

Thanks Jose. This makes more sense with the schematic and all the labels now. I have another question related to the SA0_8700 test point.

Is it expected that this test point always give about 1.7V? When I power up the board and measure the voltage of the SA0_8700 pin using the test point, I always see around 1.7V. Strangely, even when I tried to ground this pin (i.e. connect SA0-MISO-5 to GND-7), I still see 1.7V on the test point.

[reyes]

Hi TD,

No, actually SA0_8700 should be 0V since resistors R9 and R5 are 0ohms resistors connected to GND.

Just as a note, make sure you are measuring the correct test point, it could be confusing.

“SA0_8700” test point it’s the 4^th from uptodown.

Have a great day,
Jose Reyes

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[tungdao]

Hi Jose,

Yes, that's the exact test point I have been measuring. And I have been having problems with reading data and receiving DRDY signals with the board I ordered. I submitted a service request but haven't heard back yet. I think there's some problem with the board I ordered.

Thanks.

[reyes]

Hi TD,

I just do some tests using my own FRDM-STBC-AGM01 board and I can confirm that I have 0V on SA0_8700. So, it seems like you have a defective or damaged board, I would recommend you to wait until you receive an answer in your service request to ask for a replacement.

Regards,

Jose

[tungdao]

Hi Jose,

I still have not heard back from my service request. It has been a month already. Is there anyways to expedite this?

Thanks.